If you want user to be redirected back to your page from payment gate then you need to init flow with 3 parameters:
If returnUrl wasn't defined then user will end up reservation process on our Thank you page.
<body> <div id="main"></div> <script src="https://yourcompany-perfectgym-address/ClientPortal2/sdk"></script> <script> PerfectGym.ECommerce.init({ flowId: 'b64d45ff3', element: '#main', returnUrl: 'https://github.com/PerfectGym/ClientPortal.ECommerce' }); </script> </body>