How to sync Apple Account passwords on my Mac mini and iPad?

I'm confused. I have a Mac Mini and an iPad. I have the same ID on both units, but somehow, after forgetting and resetting the password on my Mac Mini, I have different passwords on each unit because each unit would not accept the password on the other unit. I have two factor verification, and when I tried to reset my password each unit referred me to the other for a code. I would like to have the same ID and password on both units. How do I do that?