Where does it say a President and VP candidate can’t reside in the same state.
Th e candidates can be from the same state. However, the electors if from that state can only vote for one of candidates for office. Example vote for Prez but not VPrez or VPrez but not Prez.
Section II Article II
“....
The Electors shall meet in their respective States, and vote by Ballot for two Persons, of whom one at least shall not be an Inhabitant of the same State with themselves.
...”