I don't want to route phone call audio to ipad, how to disable that feature?

When a phone call comes in and I want to put it on speakerphone, the option to route to my ipad is always there. Even if I sign out of my Apple account on the ipad, the option is there. Even if I'm not on the same wifi as the ipad, the option appears.

I've got the phone set to not accept imessage calls or messages from my email, only my phone number. The ipad is signed out of Apple so my email should not be tied to anything related to calls.

How do I permanently remove call audio routing to any other device?

Phone: 15Pro iOS 17.3.1

iPad: 6th gen wifi.