Are you in the US? The place to generally look is a sleep disorders center, but certified CBT-I specialists even at such centers are hard to find. Look for Gregg Jacobs' list of certified CBT I folks: https://www.cbtforinsomnia.com/clinicians-recently-trained-by-dr-jacobs/

But you probably won't find many with extensive mindfulness experience - but just ask. Write to a few. If they are comfortable creating online training, you can learn a lot from such training if you can't find someone in person.

Good luck!