I'm customizing my page to upload multiple files (photos). This is the code that I have so far and according to this link it should work: https://shopify.dev/tutorials/customize-theme-get-customization-information-for-products in the link go to "Allow file uploads" if you want to check.
{% form 'product', product, class:form_classes, data-product-form: '', enctype:"multipart/form-data" %}
            {% unless product.has_only_default_variant %}
              <div class="product-form__controls-group">
                {% for option in product.options_with_values %}
                  <div class="selector-wrapper js product-form__item">
                    <select class="single-option-selector single-option-selector-{{ section.id }} product-form__input"
                      id="SingleOptionSelector-{{ forloop.index0 }}"
                      data-index="option{{ forloop.index }}"
                    >
                      {% for value in option.values %}
                        <option value="{{ value | escape }}"{% if option.selected_value == value %} selected="selected"{% endif %}>{{ value }}</option>
                      {% endfor %}
                    </select>
                  </div>
                {% endfor %}
              </div>
            {% endunless %}
            <select name="id" id="ProductSelect-{{ section.id }}" class="product-form__variants no-js">
              {% for variant in product.variants %}
                <option value="{{ variant.id }}"
                  {%- if variant == current_variant %} selected="selected" {%- endif -%}
                >
                  {{ variant.title }}  {%- if variant.available == false %} - {{ 'products.product.sold_out' | t }}{% endif %}
                </option>
              {% endfor %}
            </select>
            {% if section.settings.show_quantity_selector %}
            {% comment %}
              <div class="product-form__controls-group">
                <div class="product-form__item">
                  <input type="number" id="Quantity-{{ section.id }}"
                    name="quantity" value="1" min="1" pattern="[0-9]*"
                    class="product-form__input product-form__input--quantity" data-quantity-input
                  >
                </div>
              </div>
                <div class="qtydiv">
                {% comment %}<label for="Quantity" class="quantity-selector">Quantity</label>{% endcomment %}
                <div class="qtybox">
                  <span class="btnqty qtyminus icon icon-minus">-</span>
                  <input type="text" id="quantity" name="quantity" value="1" min="1" class="quantity-selector quantity-input" readonly="">
                  <span class="btnqty qtyplus icon icon-plus">+</span>
                </div>
              </div>
        {% endcomment %}
            {% endif %}
            <div class="product-form__error-message-wrapper product-form__error-message-wrapper--hidden{% if section.settings.enable_payment_button %} product-form__error-message-wrapper--has-payment-button{% endif %}"
              data-error-message-wrapper
              role="alert"
            >
              <span class="visually-hidden">{{ 'general.accessibility.error' | t }} </span>
              {% include 'icon-error' %}
              <span class="product-form__error-message" data-error-message>{{ 'products.product.quantity_minimum_message' | t }}</span>
            </div>
            <div class="product-form__controls-group product-form__controls-group--submit">
              <div class="qtydiv">
                {% comment %}<label for="Quantity" class="quantity-selector">Quantity</label>{% endcomment %}
                <div class="qtybox">
                  <span class="btnqty qtyminus icon icon-minus">-</span>
                  <input type="text" id="quantity" name="quantity" value="1" min="1" class="quantity-selector quantity-input" readonly="">
                  <span class="btnqty qtyplus icon icon-plus">+</span>
                </div>
              </div>
              <div class="product-form__item product-form__item--submit
                {%- if section.settings.enable_payment_button %} product-form__item--payment-button {%- endif -%}
                {%- if product.has_only_default_variant %} product-form__item--no-variants {%- endif -%}"
              >
                <button type="submit" name="add"
                  {% unless current_variant.available %} aria-disabled="true"{% endunless %}
                  aria-label="{% unless current_variant.available %}{{ 'products.product.sold_out' | t }}{% else %}{{ 'products.product.add_to_cart' | t }}{% endunless %}"
                  class="btn product-form__cart-submit{% if section.settings.enable_payment_button %} btn--secondary-accent{% endif %}"
                  data-add-to-cart>
                  <span data-add-to-cart-text>
                    {% unless current_variant.available %}
                      {{ 'products.product.sold_out' | t }}
                    {% else %}
                      {{ 'products.product.add_to_cart' | t }}
                    {% endunless %}
                  </span>
                  <span class="hide" data-loader>
                    {% include 'icon-spinner' %}
                  </span>
                </button>
                {% if section.settings.enable_payment_button %}
                  {{ form | payment_button }}
                {% endif %}
              </div>
                    <input required class="required product-form__input" id="photo" type="file" name="properties[Photo]" multiple>
              </div>
            </div>
          {% endform %}
This is my form that according to the link must have the attribute
enctype = "multipart / form-data".
At the bottom of the form it is in input type = "file".
<input required class="required product-form__input" id="photo" type="file" name="properties[Photo]" multiple>
And this is the code in the cart-template.liquid.
<div class="list-view-item__title">
                      <a href="{{ item.url }}" class="cart__product-title" data-cart-item-title>
                        {{ item.product.title }}<br>
                        {% assign property_size = item.properties | size %}
                          {% if property_size > 0 %}
                            {% for p in item.properties %}
                                {{ item.properties.count }}
                              {% assign first_character_in_key = p.first | truncate: 1, '' %}
                              {% unless p.last == blank or first_character_in_key == '_' %}
                                {{ p.first }}:
                                {% if p.last contains '/uploads/' %}
                                  <a class="lightbox" href="{{ p.last }}">{{ property_size }}</a>
                                {% else %}
                                  {{ p.last }}
                                {% endif %}
                                <br>
                              {% endunless %}
                            {% endfor %}
                          {% endif %}
                      </a>
                    </div>
The problem is the property_size variable gets value one even if I upload two or more images, when in fact I should return the amount of properties that the item has. Can anyone help me please? What I am doing wrong?
 
    