[Plugin: Widget Logic] Display widget for specific user only

I am trying to have a widget displayed for a specific user but unfortunately I cannot get it to work.

I have found out how to get the current user id and display a text for this user only, but I don’t know how to convert to Widget Logic code.

This is what I am trying to do:

<?php
$user_id = get_current_user_id();
if ($user_id == 3) {
    echo 'Show Widget.';
}
?>

Can anyone tell me how I can get the above to work with Widget Logic?