How can I set up my Edge tags to work with my central server alarm pipeline?

What versions of Ignition are you using (both Edge & Full / Central)?

On 8.1 within Edge Gateway Config webpage (Config > Alarming > Remote Notification), you'll need to enable remote alarm notification & select the remote gateway where you'd like to send the alarm event to. Following, you should be able to select the desired remote pipeline directly from an Edge tag's alarm configuration.