Create feign configuration without using @EnableFeignClient

I have a java application thats used by another service (B) as a jar. My service is using feign client to call its downstream service. When service B makes a call to my application, the feign client configurations are not getting loaded and it shows null value for feign client variable. Is their any way to load configurations in a custom manner?

Thats the application class which is having @EnableFeignClient, but not helping as service B is directly calling service method.

Start with the application class using @EnableFeignClient and trace how service B invokes the service method when the application is packaged as a jar. Compare that path with Feign client initialization and determine whether custom configuration is a supported requirement. Done should include a reproducible case and either documented configuration behavior or a clearly scoped fix.