i have ultra watch I couldn't connect it with mobile service

Hey there Naser-Tefiku,

The first thing we want to share is an article that shows how to set up cellular on a watch, along with listing the requirements to do this: Set up cellular on Apple Watch If these are the steps you've been trying to take, we want to learn more about what's happening along with ruling out some other possible causes:

1. What exactly occurs when you try setting up cellular on your Apple Watch? The more details you provide, the better we'll understand the issue.
2. Sometimes unexpected behavior can be resolved with a restart: Restart your iPhone and Restart your Apple Watch
3. As the first step in the article had you update both your watch and iPhone, the latest versions respectively are watchOS 9.4 and iOS 16.4.1. You can check under each device for the currently installed version number under Settings > General > About.

Cheers!

A couple question you need to answer:

1. Where was the watch purchased and where do you live?
2. You have to use the very same cellular provider you use on your iPhone. Do they actually support Apple Watch?

Apple support have an article online that may help:

How to: Use your Apple Watch Ultra with a cellular network