Trump will win and the house and senate will refuse to certify the electoral votes. That is the precipice that will trigger the military. Kamala as a candidate cannot cast a vote in the senate. The constitutional crisis can only be resolved by the military.
They will have an opposing slate of electors and will cause a crisis with dueling electors, This will throw the vote back to the current house. The house will choose Trump and the senate will divide 50/50, Kamala will not be allowed to cast a tie breaking vote.