why won’t my nike run club app use my apple watch?

Hi everyone,

I have a series 5 apple watch, and i use it to workout. I recently downloaded nike run club, and love using it to run. However, it won’t use my apple watch to track my distance. Instead, it used the movement of my phone. I run indoors, and have marked on the app that I run on a treadmill. I’ve checked that my watch is connected to the app, it has all permissions turned on, and both the app and my watch are fully updated. However, it just will not use my watch to track my acvitity and distance, and only uses the movement of my phone. Any ideas on how to fix this?