Actually i'm working on the parity-bridges-common but i'm not able to transfer any custom message to other than the same format that they have provided.
./target/debug/substrate-relay send-message millau-to-rialto
--source-host localhost
--source-port $MILLAU_PORT
--source-signer //Alice
raw 020419ac
Can someone please guide me through this ?What is the raw 020419ac means? And how to edit it