JSFiddle - React, Tailwind, and code Playground

HTML

<label>
    <input type="checkbox" id="powermail_field_doruovaciaadresa2_1" />
    Show/hide
</label>
<div id="powermail_fieldwrap_331">Lorem ipsum</div>

CSS

#powermail_fieldwrap_331 {
    display: none;
}

JavaScript

document.getElementById('powermail_field_doruovaciaadresa2_1').onchange = function() {
    document.getElementById('powermail_fieldwrap_331').style.display = this.checked ? 'block' : 'none';
};