hoe to cancel beta software

• In Garmin Connect Web, click on the watch icon located in the top/right corner of the screen. 
• Click the device name
• Click on "Leave Beta Software Program."
• Click Opt Out.

Then you can either wait for the next live software update, or follow these instructions to backdate to the current live software - How to return to Live software

If you don't want to wait, the files you'll need to back date your Fenix 7 to the current live software are here at the bottom of the page - Beta Version 21.04 - 'Check for Updates' Only - Announcements - Fenix 7/Fenix 7 Pro - Epix 2/Epix 2 Pro - Enduro 2 - Quatix 7 - Marq 2 - Garmin Forums

Also, similar discussion here - What are the exact steps to backdate firmware - fēnix 7 Series - Wearables - Garmin Forums