Unable to pair my Apple Watch to iPhone 16 Pro Max

Hello! I cannot pair my Apple Watch with my iPhone 16 Pro Max. I bought the Apple Watch 2 years ago, but did not use it, and only now decided to connect it. What should I do? I managed to pair them once, but the process did not go further. I am trying to unpair these devices but it doesn't work. Could you please call me? I am very worried.

[Re-Titled by Moderator]

Original Title: ta have a roll with apple watch