Hello nayan2698,
Thanks for posting in the Apple Support Communities.
Let's confirm you're up-to-date with the latest iOS version to be sure this isn't related to a software concern. If an update is available, be sure to back up your information before installing the update. Check out the steps below for assistance with this, and you can locate more details here: Update your iPhone, iPad, or iPod touch - Apple Support
Update your iPhone, iPad, or iPod touch wirelessly
1. Back up your device using iCloud or your computer.
2. Plug your device into power and connect to the internet with Wi-Fi.
3. Go to Settings > General, then tap Software Update.
4. If you see two software update options available, choose the one that you want to install.

5. Tap Install Now. If you see Download and Install instead, tap it to download the update, enter your passcode, then tap Install Now. If you don't know your passcode, learn what to do.
You might see that your device is up to date and that there's an upgrade available. For example, even if your device is up to date with the latest version of iOS 14, there might be an option to upgrade to iOS 15. You might want to upgrade iOS when you pair an accessory with iPhone.
If you're up-to-date, try restarting your iPhone then checking if this remains. In addition, check to see if that appears when using the camera in a third-party app. If this remains after a restart and in a third party app, you'll want to Contact Apple Support to check into service options. If you need assistance with a restart, use this resource: Restart your iPhone - Apple Support
We hope that helps.
Have a great day!