  Schubitopes were introduced by Monical, Tokcan and Yong as a specific family
of generalized permutohedra. It was proven by Fink, M\'esz\'aros and
St.$\,$Dizier that Schubitopes are the Newton polytopes of the dual characters
of flagged Weyl modules. Important cases of Schubitopes include the Newton
polytopes of Schubert polynomials and key polynomials. In this paper, we
develop a combinatorial rule to generate the vertices of Schubitopes. As an
application, we show that the vertices of the Newton polytope of a key
polynomial can be generated by permutations in a lower interval in the Bruhat
order, settling a conjecture of Monical, Tokcan and Yong.
