How to identify a user login from a new device

Question

I am working on a functionality to send an email to user whenever a they log in to my website with a new device. For example if a user logged in to their account from iOS app, notify them that a new device login is detected. If at a later point, same user logs in from web browser, send another notification that a new device login is detected.

I came across UIDevice uniqueIdentifier deprecated - What to do now? and Is there a unique Android device ID?.

I wanted to confirm few things:

1. Does UIDeviceIDentifierForVendor for iOS change with iOS updates and app version updates?
2. A unique Device id - (UIDeviceIDentifierForVendor for iOS - https://developer.apple.com/documentation/uikit/uidevice/1620059-identifierforvendor and IMEI for android(since hardware identifier would be sufficient for our use-case) - https://developer.android.com/training/articles/user-data-ids should be sufficient for my use-case.
3. Is there any similar way to uniquely identify a web browser or is a persistent cookie the only option to uniquely identify a web browser - Using cookies with Android volley library?

Note: Feel free to suggest any other better way to uniquely identify user devices(if any).

I looked through different questions on stack overflow and browsed through different blogs describing Device fingerprinting and offering services to get a device fingerprint.

I'm expecting to find the best practices around uniquely identifying devices and methods used widely for uniquely identifying user devices on iOs, Android and Web browsers.