That would be shades of Charles I entering the House of Commons to arrest members prior to the English Civil War.
Not a good thing.
The Congress and the state legislatures have exclusive control over their chambers. The reason for that in the English speaking world is due to that event.
I’m not advocating that he just show up. I doubt he would be granted admittance, as someone else noted.
Calling for a special session of Congress, provided the right conditions are met, is a Presidential power that is expressly given to the President per the U.S. Constitution.