How can I get my DD19 to take a shower

[gabsdot45]

How can I get my DD19 to take a shower without being reminded.
This is an issue that I have been working on with her since she was about 8 and old enough to bath independantly. I've tried so many things and nothing works.
Even if she is reminded she won't do it. I know it's to do with her ADHD, she gets distracted to easily but she is 19 and she often smells so bad.
She is also so oppositional so being asked to do anything often ends up in an argument.
Any ideas

A consistent routine with a discreet phone reminder may work better than repeated prompting. Giving her some choice over the timing can also reduce resistance and help her feel more in control.

Dc1 with asd only showers because we implemented a very strict morning routine. But that would only work if dd would stick to a routine.
It was one of our hardest areas to crack. Dc1 now has the opposite issue in that they can't start the day without a 20 min shower!