How to synch ripped Albums in Music on my iMac to Music on my iphone

If you subscribe to the iTunes Match subscription service, or to the Apple Music subscription service, I believe that you can use "Sync Library" to sync music across devices.

I have an Apple Music subscription, but I prefer to keep Sync Library turned off, and use manual synchronization to get music from my CDs onto my iPhone.

This is the model where you attach your iPhone (or iPad or iPod) to a "master" Mac or PC, and replace the music on the portable device with a selection from the library on the Mac or PC. In the old days, iTunes was the place where you both imported music from CD and synchronized it to portable devices. Since Catalina, you import Music in the Music application, and synchronize it to portable devices using the Finder.

Sync your iPhone, iPad, or iPod using your computer - Apple Support