Open the screen recording tool on your device
On Windows, press Windows + G and start recording from the Game Bar
On Mac, press Shift + Command + 5 and choose Record Entire Screen or Record Selected Portion
On iPhone, add Screen Recording to Control Center, then tap the record button
On Android, swipe down the quick settings panel and tap Screen Recorder if available
Select the screen or window you want to record
Start the recording
Stop the recording when finished
Save the recording to your device