phpengine/ui/login.tpl

<div class="text-center mx-auto col-md-7 mt-5">
    <img src="{{@BASEURL}}/ui/images/logo.png" alt="" class="img-fluid">
    <form enctype="multipart/form-data" action="loginform" method="POST">
        <h1 class="mb-4" style="font-size: 4vw">Login</h1>
        <label for="username" class="sr-only">username</label>
        <input type="text" name="username" id="username" class="form-control mb-1" placeholder="Username" required autofocus autocomplete="false">
        <label for="password" class="sr-only">Password</label>
        <input type="password" name="password" id="password" class="form-control mb-1" placeholder="Password" required autocomplete="false">
        <button class="btn btn-lg btn-warning btn-block" type="submit">Invia</button>
    </form>
</div>