You can check the identification code of the device you are using by following the steps below.
▼Get the Identification Code (Device ID)
Mobile App: https://teachme.jp/8/manuals/9920280
If an administrator wishes to check a registered identification code, please refer to the following.
▼Manually register, edit, and delete Specific code (Device ID). (Web Browser)
https://teachme.jp/8/manuals/9124481/
Related: What is an Identification Code (formerly: Device ID)?
https://help.teachme.jp/hc/en-us/articles/900006443243