Switching from pod to SPM-- How do I add Firebase?

I successfully migrated my capacitor iOS app from Cocoapods to SPM (I deleted the old app and then recreated from scratch with the commands).

I’m using Firebase Cloud Messaging to handle push notifications, so I need to add the Firebase library. The official docs (Push Notifications - Firebase | Capacitor Documentation) still describe how to do it with pods, but Firebase supports SPM (Options to install Firebase in your Apple app  |  Firebase for Apple platforms). I went to edit the Package.swift file, but it clearly states // DO NOT MODIFY THIS FILE - managed by Capacitor CLI commands.

I couldn’t find a Capacitor CLI command to add a package… How do I add Firebase SDK?

So I didn’t figure out how to do this from the command line, but it’s quite easy from XCode: FileAdd New Package.