I use a backpack from High Sierra. It slips over my roller handle and has more pockets than I need. Look here...https://shop.highsierra.com/backpacks/

Find several you like and then search Amazon, Costco, etc. I got mine at Costco for half the price of the link above.

I’m a big fan of the backpack as it gives me a comfortable bag to take on a layover walkabout.

Also, when you walk up the stairs to the plane, it leaves a hand free to use the handrail. You may laugh at this but....when the company denies workers comp after your slip and fall because your hands were full you won’t laugh anymore.