How to add Authorization token to gRPC requests

I tired adding authorization token to new gRPC requests similar to how I add in for HTTP requests 

GRPC localhost:6565/serviceAPI/GetData
Authorization: Bearer {{auth_token}}

auth_token is present in the env file

I keep getting 

io.grpc.StatusRuntimeException: UNAUTHENTICATED: Authorization token is missing

Can someone help identify the problem here?

Intellij version: IntelliJ IDEA 2021.3.2 (Ultimate Edition)