Documentation about PRA remote app and remote desktop agent

Check these articles, if they can be helpful for your use cases.

Remote Support / Privileged Remote Access - SecureApp jump session using RDP does not connect - How to setup RDP SecureApp

Protocol Tunnel Jump shortcuts

I can see that we can inject credential, is it via the protocol tunnel?? need to use the SQL Management studio. I saw we need  remote desktop agent to inject credential.

Any information about this agent? How it works and how to set it?