Force new subscriber's username to be their email address during sign up for Leaky Paywall

force_email_as_username.php

<?php 

add_filter('leaky_paywall_userdata_before_user_create', 'zeen101_force_email_for_new_user' );

function zeen101_force_email_for_new_user( $userdata ) {

	$userdata['user_login'] = $userdata['user_email'];
	return $userdata;
	
}