Why I cannot assing an element of array to another object propety?

Question

Hi my problem is I want to assign "John" to a task in data() of Vue.js and I get an error in console like this : App.vue:37 Uncaught TypeError: Cannot read properties of undefined (reading '0');.

Here is fragment of my code:

data() {
    return {
        employees: [
            {
                name: 'John'
            },
        ],

        tasks: [
            {
                name: "Work out in the gym!",
                assingTo: this.employess[0]
            }
        ]
    };
},