My sister, brother, and I all have this one. It’s nice bc they can stand and sit and still see out. Plus, if you travel with your friend, it expands so he can really relax in it.

https://www.amazon.com/Pecute-Ventilated-Breathable-Expandable-Traveling/dp/B08GSC79ZJ/ref=mp_s_a_1_15?dchild=1&keywords=cat%2Bbackpack&qid=1628203969&sprefix=cat%2Bba&sr=8-15&th=1&psc=1