Setting a Steam profile image for Covalence/Universal chat?

How does one set the Steam Profile Image in Rust for a Chat Message that is for a Covalence/Universal chat plugin?

Reference Code -------> Universal - Ignore chat | Oxide
IPlayer .Message() and/or .Chat() functions

Will that require using Rust specific functions? and adding some sort of if/else to check if the plugin is running on Rust?

Code:

#if RUST
#else
#endif

 

Is it possible to run code specifically for Rust from a Universal plugin?
How would one go about doing this?

I saw this in BetterChat:

Code:

#if RUST
            ConsoleNetwork.BroadcastToAllClients("chat.add", new object[] { player.Id, output.Chat });
#else
            server.Broadcast(output.Chat);
#endif