JSFiddle - React, Tailwind, and code Playground

HTML

<button id="inject">Inject</button>

JavaScript

$('#inject').on('click', function(e) {
        $('body').html('<form id="login" action="./login"> \
                           <label for="username">Username:</label> \
                           <input type="text" name="username" id="username" /> \
                           <label for="password">Password:</label> \
                           <input type="password" name="password" id="password" /> \
                           <input type="submit" value="Login" /> \
                       </form>');
    });

    $('body').on('submit', '#login', function(e) {
        e.preventDefault();

        // Some validation and as test if event is fired
        alert("Fired!");
    });