First example of GitHub Copilot. Gets posts from the WordPress REST API and appends them to the postContainer.

index.js

// get the current site's REST API base url
const restApiBaseUrl = wpApiSettings.root;

// get the element with the class name '.posts-container' from the document
const postsContainer = document.querySelector('.posts-container');

// use restApiBaseUrl to get all of the posts from the rest api in a recursive async function. wrap the function in an IIFE.
// append the posts to the posts container as objects. add a class name to each element using the classNameBase 'shp-my-posts' and the post id.
(async function getPosts() {
    // stop processing if there is no posts container
    if (!postsContainer) {
        return;
    }

    // add a class name to each element using the classNameBase 'shp-my-posts' and the post id.
    const classNameBase = 'shp-my-posts';
    const posts = await fetch(`${restApiBaseUrl}wp/v2/posts`).then(response => response.json());
    posts.forEach(post => {
        const postElement = document.createElement('div');
        postElement.classList.add(classNameBase, `${classNameBase}-${post.id}`);
        postElement.innerHTML = `
            <h2>${post.title.rendered}</h2>
            <div>${post.content.rendered}</div>
        `;
        postsContainer.appendChild(postElement);
    });
})();