There are a few potential reasons why iOS 15 might not be appearing as an update on your iPhone XR:
-Your iPhone XR might not be compatible with iOS 15. To check if your device is compatible with the new software, you can go to Settings > General > About > Software Update. If iOS 15 is available, it should show up here.
-If you don't see iOS 15 listed, it could be because your iPhone XR is too old and isn't supported by the new software. In this case, you'll need to upgrade to a newer iPhone model that is compatible with iOS 15.
-It's also possible that you might have installed a beta version of iOS 15 on your iPhone XR, which is why the public release isn't appearing as an update. To check if this is the case, go to Settings > General > About > Software Update. If you see a message that says "Your software is up to date," this means you have the public release of iOS 15 installed.
-If you still don't see iOS 15 listed as an update, it's possible that your iPhone XR is connected to a computer that has an older version of iTunes installed. Try updating iTunes to the