It’s certainly debatable, but shutting down agencies created and authorized by Congress and refusing to distribute funding legislated by Congress seems to be an overstep of executive power, and therefore an undermining of Congress’s power.

My main point was that ousting an incumbent or defying an election is not a requirement for something to be a coup, as the previous comment was suggesting. A legitimately elected official seizing more power than they are legally entitled to is a form of coup.