Unsuccessful pairing of Apple Watch Ultra
Why can’t I connect my A2589 Apple Watch Ultra??
[Re-Titled By Moderator]
Does your carrier support your Apple Watch Ultra? Your model A2859 seems to be optimized for the use in China mainland or Hongkong/Macao.
Apple Watch - Carriers - Apple
Do you get any error messages, if you want to set it up, as described in this article?
Set up your Apple Watch - Apple Support
General troubleshooting can also be found here:
If you can't pair an Apple Watch with your iPhone - Apple Support