i have the following code for grpc:

val port = 9090
val channel = ManagedChannelBuilder
            .forAddress("grpc.friday.fastek.ph", port)
            .useTransportSecurity()
            .build()
try {
val client = FastekBeepClient(channel)
client.stmBalance()

i added the headers this way…

val metadata = io.grpc.Metadata()
metadata.put(Metadata.Key.of("authorization", Metadata.ASCII_STRING_MARSHALLER),"Bearer token...")

then call the rpc method this way..

client.withInterceptors(MetadataUtils.newAttachHeadersInterceptor(metadata))
    .stmBalance(intialRequest))

take note that i needed to add authorization as header as it was needed

Im still getting UNAVAILABLE status but when i tried it on postman it was working..