or a selfie of the provider?

Depends on yourself.

Do you mind sharing a selfie 🤳 with a smile?  
I use real life id for verification purposes. I love to see whom I am sharing my time with. I do love a good selfie with a smile. 😃

Find the provider that fits your needs. If you don’t feel comfortable sharing don’t. There are lots of providers who rely solely on references from providers they don’t know personally. Everyone is so very different & that’s okay. The fun part about this hobby lifestyle is there is something for everyone. Happy hunting. Smile for me! 😜

Are you married?
Do you have a social media presence that she could exploit?
Do you have a job that would be in jeopardy if you are discovered to solicit sex workers?

That said, JUST a selfie is a pretty low level of verification on her part.

 
If you do proceed, take a unique selfie, not something you already have. Consider using a photo editor to slightly modify your appearance, but keep close enough so she doesn't turn you away at the door.

If you are going to be sending pictures of yourself, use one that is online somewhere.  This way if they attempt to use it as extortion evidence, you can say they just copied it from online.  

I have been asked to send selfie with license and proof of insurance.

I politely say I’m not comfortable w this, thank you.  Generally we go our separate ways.  You are dealing in an illegal world here and not all people are nice!