Download tvOS 15 Beta Profile:

1 Open Settings app

For Installing tvOS 15 Beta Profile Open the Settings app and move to General – Privacy – Send Apple TV Analytics.
Apple TV beta software
Apple TV beta software

2 Do some trick

Now you can download tvOS 15 Beta Profile . When you have Share Apple TV Analytics selected, don’t click on it. Instead, press the Play/Pause button on the remote and it will open the Add Profile menu, press Play/Pause button again on this option.
Apple TV beta software
Apple TV beta software

3 Install profile

Apple TV beta software

4 Reboot your Apple TV

Apple TV beta software

5 Turn off Get Beta Updates

Make sure Settings – System – Software Updates – Get Beta Updates set to OFF.

6 Download Now