Coros have sent me an API key etc. and I am busy with the integration. Thanks to everyone who chased them on this.
I need someone with a Coros watch to authorise Intervals.icu so I can have some data to test with. If you would like to help with that please send me a DM. I will enable the Coros box in settings for you. It only does auth now but this will give me an access token to test with. Thanks.