Something to verify first: Are you using the latest version of the app? (i.e Did you download the app in the last week?)
If you have then the following steps may help to solve your issue:
- Go to the Home app in iOS
- Create a Home; if it is your first time setting up Homekit, clicking "Get Started"will create a Home automatically and you should be able to then go and pair your Mysa
- Try pairing the thermostat again, it should work now
If you're still having trouble with your thermostat. Please reach out to our team if you have any further questions!