Does the Modem select the USIM application on the UICC and is there something like a switch

I’m working on adding the EAP-TLS authentication method to my UICC. Who decides which application on the
UICC does the authentication for the 5G network? If it is the Modem does it have something like a switch where
it is extendable for another authentication method?

Dear @fuzetea
Sorry for the late. Did you solve your question now?