Trump hasn't been charged with "insurrection."

But the 14th Amendment doesn't say who determines whether he did so engage. The states? Congress? The Supreme Court? It's all very murky.

He was charged with inciting an insurrection in his second impeachment but was acquitted by the Senate. Impeachment is a political, not a judicial, procedure. He could still be charged criminally - and at the time of his acquittal, McConnell, Graham, McCarthy, and others insisted that he should be. What changed their minds and turned them back into ardent supporters is unclear.

The current charges against Trump in the 1/6 case are:

Conspiracy to defraud the government [with false electors]

Conspiracy against the right to vote [by attempting with others to overturn the legitimate result of an election]

Conspiracy to obstruct an official proceeding [by exhorting the crowd (again with others) to march to the Capitol and "fight like hell"]

Obstruction of an official proceeding [by doing nothing to call off the rioters once they were in the building]