Majority vote I believe?
“Twenty-Fifth Amendment
Section 1
In case of the removal of the President from office or of his death or resignation, the Vice President shall become President.
Section 2
Whenever there is a vacancy in the office of the Vice President, the President shall nominate a Vice President who shall take office upon confirmation by a majority vote of both Houses of Congress.”
https://constitution.congress.gov/constitution/amendment-25/
https://constitution.congress.gov/constitution/amendment-25/
… Whenever there is a vacancy in the office of the Vice President, the President shall nominate a Vice President who shall take office upon confirmation by a majority vote of both Houses of Congress...