Remove CVV from the checkout page and don't require it.

my_pmpro_show_cvv.php

<?php
/**
 * Remove CVV from the checkout page and don't require it.
 */

// Removes the field from the checkout page.
function my_pmpro_show_cvv( $show ) {
	return false;
}
add_filter( 'pmpro_show_cvv', 'my_pmpro_show_cvv' );

// Removes CVV from the required fields array
function my_pmpro_required_billing_fields_unset_cvv( $fields ) {
	unset( $fields['CVV'] );
	return $fields;
}
add_filter( 'pmpro_required_billing_fields', 'my_pmpro_required_billing_fields' );

This recipe is included in the blog post on "Remove the CVV Field From the Checkout and Billing Pages" at Paid Memberships Pro here: https://www.paidmembershipspro.com/remove-the-cvv-field-from-the-checkout-and-billing-pages/