Sometimes, a Technical Support rep will ask for a screen capture/recording as part of the troubleshooting process.
Steps to add Screen Record to your iPhone:
Tap Control Center
Scroll down to Included Controls. If Screen Recording is listed under Included Controls then you are all set. You can exit the Control Panel.
If Screen Record is not listed under Included Controls, then perform the following step(s)
Scroll down to More Controls
Locate Screen Recordings
Tap the GREEN Plus sign in front of the line that reads Screen Recordings
Tap Settings at the top Left to exit the menu after you have added it.