stripe-cf-metadata.php

<?php
// Paste this into functions.php or a plugin like Code Snippets

function add_stripe_payment_args($args, $txn = false, $sub = false) {
  if($txn) {
    $user = $txn->user();
    $args['metadata']['mepr_fatturazione_elettronica'] = get_user_meta($user->ID, 'mepr_fatturazione_elettronica', true);
  }
  return $args;
}
add_filter('mepr_stripe_payment_args', 'add_stripe_payment_args', 11, 2);
add_filter('mepr_stripe_payment_intent_args', 'add_stripe_payment_args', 11, 2);
add_filter('mepr_stripe_setup_intent_args', 'add_stripe_payment_args', 11, 2);
add_filter('mepr_stripe_subscription_args', 'add_stripe_payment_args', 11, 3);