Sandobox test fail

Thank you, Guys, in advance
im new with this im getting fail when test the form get this

get this error: Payment Failed got right sandbox paramethers and testing with CC 41111

:wave: Looks like you are getting the token to pass to the CreatePayment request as the source_id however I’m not seeing any API calls to CreatePayment with any of the source_ids. Do you have the backend server correctly setup?