JSFiddle - React, Tailwind, and code Playground

HTML

<form id="foo">
    <input id="test"/>
    <input type="submit"/>
</form>

JavaScript

document.getElementById("foo").onsubmit = function(e) {

    if (document.getElementById("test").value == "test") {
        return true;
    } else {
        e.preventDefault();
    }

}