JSFiddle - React, Tailwind, and code Playground

HTML

<h3 class="_52jh _5pxc"><a href="/urldouser?ref=bookmarks">Nome Do Usuário 1</a></h3>
<h3 class="_52jh _5pxc"><a href="/urldouser?ref=bookmarks">Nome Do Usuário 2</a></h3>
<h3 class="_52jh _5pxc"><a href="/urldouser?ref=bookmarks">Nome Do Usuário 3</a></h3>
<h3 class="_52jh _5pxc"><a href="/urldouser?ref=bookmarks">Nome Do Usuário 4</a></h3>
<h3 class="_52jh _5pxc"><a href="/urldouser?ref=bookmarks">Nome Do Usuário 5</a></h3>

JavaScript

var nomes = [].map.call(document.querySelectorAll('._52jh._5pxc a'), function(el) {
    return el.innerHTML;
});

alert(JSON.stringify(nomes, null, 4));