How to check my UserID?

Kindly refer to the below on how to check your userID in respective devices:

iOS Device:

Tap the Menu on top left corner > Go to My Account > Device Name: 

Android Device:

Tap the Menu on top left corner > Select "My Account" > Tap Device

Mac Device:

Tap the Menu on the top left corner > Select "About us" 

Then, double click the Master Logo and the userID will be copied

Window Device:

Tap the Menu on the side bar > Select "Setting" 

Then, select "General Setting" 

Double click on the version wording and the userID will appear