As you may be aware the Exchange Hybrid Agent has been in preview fro quite some time (see https://t.co/dAB3IKJw1z).
The Hybrid Agent is aimed to provide a simpler way to implement Exchange Hybrid between Exchange on-premises and Exchange Online.
Well, good news, the Hybrid Agent is now generally available (GA).
Firs thing to know is if you were using the Hybrid Agent during the preview, you will have first to uninstall the current installation before deploying the new/GA version (available from https://aka.ms/hybridagentinstaller).
Then if you are going deploying it for the first time, you need to review the requirements listed in the documentation here https://docs.microsoft.com/en-us/exchange/hybrid-deployment/hybrid-agent#system-requirements