I want to upgrade iCloud space, but I only see options to downgrade

I don't see the right category, I apologize. I have Apple 1 Family and need to upgrade storage but can't see anything about how...In April when some annual subscriptions I paid for finally expire, we will go to the $30/mo. plan instead of the $20 but I'm not sure how much the memory upgrade is or if it's included with the Apple1 plan...I just read a bunch about canceling