How to computer(having Any OS) UUID to uniquely identify the device before login?

I am developing a multi-exchange trading platform like https://app.bitsgap.com/tradin.
I am stuck at device authenticate process. Bitsgap doing this well. If you logged in using different browsers but from same PC then it will not demand Email verification to allow that device. but if you change the PC, it will prompt you to authorize the device from the email link. and once you authorize it by clicking on the link sent. then only that other device can be login using those credentials.

So my requirement is anyone tries to log in using the same credentials on other devices having Windows, Linux, Mac, or any other OS It should ask email authorization But I don't know how to get device unique id