I think the “Upgrade now” is a nag pop-up to purchase a licence, or enter your existing licence key into Settings > My Subscription.
You may be happier rolling back to v6.39 (in the hope that they may at sometime get CCleaner7 actually fit for purpose).
How to Roll Back from v7 to v6.39
Follow ALL of the instructions, particularly about turning off the Automatic Updating.
