Error: No Web Service Set in Login Gate (Login)

I am trying to create a login page that calls api from a remote MySQL database. When I try to compile, I always receive an error: No Web Service Set in Login Gate (Login). However, when I try to configure Web Service for my Login Gate, the drop-down menu doesn’t give me an option. The only 2 options under Service are:

1.No set (by default, this is selected)
2.No targets in this project

I need someone to help me how to set up targets in the project in order to fix this error.

Thanks in advance!

Screen Shot 2022-09-07 at 11.11.06 am