confirmation link also sent to user email however instead of redirect to {application.callback_domain}/my-confirmation i get error :
"{"name":"BadRequestError","code":"invalid_result_url","description":"invalid result url: /my-confirmation?email=myemail@my.com&message=This%20URL%20can%20be%20used%20only%20once&success=false","statusCode":400}"
After receiving the redirect error, could you check if the user was verified on the backend? If the verification was successfully completed on the backend the issue may be with the result_url . Can you double check the values being passed are correct?
Also, do you have multiple clients or did you create the user manually?