Shortcode: [copythis] write to clipboard

functions.php

<?php
// [copythis]This will be copied[/copythis]
// @link https://gist.github.com/cliffordp/fe86cc09d5c6250453fc4c8ccf763e5b This snippet.

add_shortcode( 'copythis', function( $atts, $content = null ) {
    return sprintf(
        '<div class="copythis">%s</div>
<button onclick="navigator.clipboard.writeText(this.previousElementSibling.textContent)">Copy This</button>',
        $content);
});