How do I save my pictures on iCloud without them getting deleted when I deleted pictures from my phone to make more room

You can’t. iCloud is a syncing service, not an archive; it mirrors what is on your phone. If you go to Settings/Photos and turn on Optimize Storage it will save lower quality versions of your photos on your phone but keep the full resolution photos in iCloud.

There is a way, but it involves severing the connection between your iPhone and iCloud Photos.

Settings > Photos > iCloud Photos =“off”.

Then you can do whatever you want with your iPhone’s photos without affecting your iCloud Photos.

But that means leaving it off forever. If you ever turn it on all of your photos will come back.

Yes, I agree. It would be a drastic method.