JSFiddle - React, Tailwind, and code Playground

HTML

<label>
    <input type="checkbox" data-name="Продукт 1"/>
    <span>Продукт 1</span>
</label>
<label>
    <input type="checkbox" data-name="Продукт 2"/>
    <span>Продукт 2</span>
</label>
<label>
    <input type="checkbox" data-name="Продукт 3"/>
    <span>Продукт 3</span>
</label>

<textarea></textarea>
<input type="button" value="Расчитать"/>

JavaScript

console.clear();

function build () {
    var selected = [];
    $('input[type=checkbox]:checked').each(function () {
        selected.push($(this).attr('data-name'));
    })
    $("textarea").val(selected.join(', '));
}


$("input[type=button]").click(build);