IntelliJ can't find Java class

Question

I'm using IntelliJ Idea for a small project. I'm using the library ru.perveevm.polygon-api.

My Main.java looks like:

import ru.perveevm.polygon.api.PolygonSession;

class Main {
    public static void main(String[] args) throws Exception {
        PolygonSession session = new PolygonSession("KEY1", "KEY2");
    }
}

My pom.xml:

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <packaging>pom</packaging>

    <groupId>org.example</groupId>
    <artifactId>creatingLatex</artifactId>
    <version>1.0-SNAPSHOT</version>

    <properties>
        <maven.compiler.source>17</maven.compiler.source>
        <maven.compiler.target>17</maven.compiler.target>
    </properties>

    <repositories>
        <repository>
            <id>polygon-api-mvn-repo</id>
            <url>https://raw.github.com/perveevm/polygon-api/mvn-repo/</url>
            <snapshots>
                <enabled>true</enabled>
                <updatePolicy>always</updatePolicy>
            </snapshots>
        </repository>
    </repositories>

    <dependencies>
        <dependency>
            <groupId>ru.perveevm</groupId>
            <artifactId>polygon-api</artifactId>
            <version>0.3</version>
        </dependency>
    </dependencies>

</project>

Also I downloaded that package and added it to the project structure:

I can run it, but IntelliJ can't find PolygonSession and shows "Cannot resolve symbol 'PolygonSession'". Because of that it doesn't suggest auto-complete and I don't like that.

What should I do?