To add, most private campsites. States parks would not. But there might be somewhere local to wash. Or get one of these

https://www.amazon.com/Mobile-Washer-Portable-Clothes-Agitator/dp/B084D2FRZ8

You don't want to combine your shitter and shower that's gross. Here just use this and a bucket: https://www.amazon.com/gp/aw/d/B084D2FRZ8/

Or one of these https://www.amazon.com/gp/aw/d/B08Z3GD7KN/