JSFiddle - React, Tailwind, and code Playground

HTML

<a id="toggleLink" href="javascript:void(0);" onclick="viewdiv('mydiv');" data-text-show="Спрятать блок" data-text-hide="Показать блок">Показать блок</a>
<div id="mydiv" style="display:none;">text text text</div>

<script>
    function viewdiv(id) {
        var el = document.getElementById(id);
        var link = document.getElementById('toggleLink');
        if (el.style.display == "block") {
            el.style.display = "none";
            link.innerText = link.getAttribute('data-text-hide');
        } else {
            el.style.display = "block";
            link.innerText = link.getAttribute('data-text-show');
        }
    }

</script>