can’t update my apple watch

Hi

First update your iPhone to the latest compatible software version:

Update the iOS on your iPhone, iPad, or iPod touch - Apple Support

Then follow the remaining steps to update your Apple Watch to the latest compatible software version:

Update your Apple Watch - Apple Support

If you are unable to install the update, then it may help to follow the steps in the second article under the headings "If you need help updating" and/or "If you installed an iOS or watchOS beta or developer seed" as appropriate.

If the issue persists, then it may help to unpair and re-pair your Apple Watch. The software will be updated as part of the process. Again be sure to update your iPhone to the latest compatible version of iOS first:

• Unpair your Apple Watch and iPhone - Apple Support
• Set up your Apple Watch - Apple Support