Using custom post type to feed a dropdown (Woo order-id into wpforms)

Using the plugin wpForms, I can auto-populate a dropdown with Custom Post Types (they call it “Dynamic Post Type Source”). Say I wanted to use this functionality to auto-populate a dropdown with order-ids from WooCommerce, so a logged-in-user can choose between the users orders.

I’ve written the code for getting a logged-in-user order-id’s, so how would I make a CPT that would not really create new posts, but instead be populated with a logged-in-users order-ids at run time (while the user is at a page with the form dropdown on it)?

Already asked wpForms for support, they did not want to help.

Code for getting the User Order-ids:

function woo_get_orderids_per_user( $  content) {  $  userID = get_current_user_id();  if( $  userID > 0 ) {          $  orders= wc_get_orders(array(             'customer_id' => $  userID,             'return' => 'ids',         ));           foreach ($  orders as $  oids) {              $  order = wc_get_order( $  oids );             $  items = $  order->get_items();              foreach ( $  items as $  item ) {                 $  product = wc_get_product( $  item['product_id'] );                 $  productname = $  product->get_name();                 echo('<br> Product name: ');                 print_r($  productname . ' (ordrenummer: ' . $  oids . ')');             }         }  $  content = str_replace( '{woo_orderid}', $  productname . ' (Ordre ID: ' . $  oids . ')', $  content );  return $  content; }  else {     return; } 

}