What have you tried? Have you got in with her? We do painting baths which my little girl enjoys. She went through a phase of not wanting a bath, but it didn’t last a year.
Perhaps put some towels down and try a paddling pool with warm water in the lounge or kitchen?
Have you tried putting her in the shower? Mine won’t do the bathtub either so we do a shower with toy trucks, animals, & crayons! He doesn’t mind getting in most days No advice on the hair washing though bc same! It’s a struggle & he cries the entire time we’re doing it. I’ve tried a ton of different things (removable shower head, rinsing with a cup, covering his face with a towel, letting him wash it himself, different brands of soap, singing songs, etc.) & so far nothing seems to help