1- Open the view you wish to record
2- Hit the Windows Key + Alt + R to start screen recording. A small recording widget showing how long you've been recording appears somewhere on the screen, most likely in a corner
(Green box in this example)
3- Click the Microphone ON (it usually defaults to OFF)
4- Perform whatever actions you want and speak normally into your microphone to record audio. You can also mute the mic if you don't want to capture any sound.
5- Hit the Windows Key + Alt + R again to stop screen recording. You can also hit the stop button on the widget.
You will get an alert that says "Game clip recorded. If you click on it, you will go into the Gallery section of the Gamebar app and be able to preview the video you captured.
You can also find the MP4 file you recorded in Settings->Gaming->Captures
6- Once there, you should be able to drag and drop it into the body of the ticket/email/wherever you need to share it. It should create an attachment.