sample code for em_booking_save filter

<?php

function em_sample_snippet( $result, $EM_Booking ){

   $bookingname = $EM_Booking->booking_meta['registration']['field_id']; //replace this with the field ID you used in your Events > Forms Editor

   //add your Thrive Apprentice code here passing the $bookingname or other info you need.



  return $result;
}
add_filter('em_booking_save', 'em_sample_snippet', 100, 2);