<?php
/**
 * This will change the Manual Payment label on the registration
 * form to the text you specify below.
 */
add_filter( 'rcp_payment_gateways', function( $gateways ) {
	$gateways['manual']['label'] = 'Send Check'; // change 'Send Check' to whatever you want.
	return $gateways;
});
Change manual payment label on registration form
Change manual payment label on registration form
