Looking for a booster Sear the recline so my son head won’t hang forward if he fall asleep

I don't think boosters seats recline. It's typically convertible car seats in 5 point harness modes that recline. My daughter has a Graco 4ever but that could only be reclined in rear facing mode.

Get a strap protector or whatever they are called. Your son can rest his head on it when he sleeps

Do NOT use strap covers or anything else that doesn’t go with the car seat please. Also booster seats none of them recline. If he’s 5 I would recommend him still staying in a 5 point harness until he had more head control when sleeping.