Short answer
Use an iPhone as a Mac controller by installing the Remote Comp Mac menu bar agent, pairing from the trusted host, confirming the route, testing the first task, and ending or revoking access when the session is done.
Install the host agent
Keep the Mac app in Applications so OS permissions and updates stay attached to a stable path.
Pair from the trusted host
Start the pairing flow from the Mac that owns the work. Enter or scan the code on the phone controller only after the host shows the setup path.
Run a route and latency check
Before relying on the session, record route state and test the exact task you plan to perform.