E-Mail only Registration / No Username

In Restrict Content Pro I can remove the username from the Registration form by adding a filter.

Can I do the same in the free version somehow?

https://docs.restrictcontentpro.com/article/1743-email-only-registration

<?php
/**
 * This will remove the username requirement on the registration form
 * and use the email address as the username.
 */
function jp_rcp_user_registration_data( $user ) {
	rcp_errors()->remove( 'username_empty' );
	$user['login'] = $user['email'];
	return $user;
}

add_filter( 'rcp_user_registration_data', 'jp_rcp_user_registration_data' );