Best way to take camera on flight

I did a couple of one bag trips on frontier/spirit with my Cotopaxi Allpa 28 as personal item without buying additional baggage. But now I have a new traveling partner, a Sony A6300 with two lenses.

There’s absolutely no way I can safely cram the camera and the lenses into the bag, it’s already pretty full. Is there a way I can still carry it on the plane without facing baggage charges? I’m thinking of a belt clip for the camera and one lens and putting the other lens in the bag. Would this wok?