You are very confused
There was an offer days before, which was rejected by the Legislative Branch of government.
We know there was an offer, because the Capitol Police chief stated there was, and he made that statement prior to Jan. 6th.
We also not that the Metropolitan Police requested and accepted an offer for the National Guard, because there was over 300 National Guard troops attached to Washington D.C.'s Metropolitan police.
You should just face the fact. The Capitol Police could of stopped whatever you call, the Trump rally. Call it an insurrection, the Capitol Police could of stopped it with no help from anyone. They allowed it to happen, even if they pushed back on the crowd, in a few places.
One armed Capitol Police officer at each door and window, ordered to stop it, would of stopped it. Nancy Pelosi never gave the order, the Sergeant of Arms never gave the order, the Capitol Police Chief never gave the order.