Using the Authentication feature, is there a way to get the credentials during a normal call, I must check if a specific user is allowed to can a specific api or not....

What @Dennis Schröder wants to say with this link:

You can get the generated Principal instance inside your handler with:

val principal: UserIdPrincipal? = call.authentication.principal<UserIdPrincipal>()

yes but what If i am in a route already where i can access a call only

call.user will return user 😉