Watch OS 8.6
On the iPhone associated with your Apple Watch, go to developer.apple.com.
Now, select watchOS.
If asked, sign in with your Apple ID.
When prompted for permission to install a profile, tap Allow.
Start the installation.
When prompted, enter your Passcode.
To confirm, tap Install.
To restart your Apple Watch, tap Restart.
The installation process resumes after your Apple Watch has rebooted
Apple provided the ability to update your Apple Watch through the Settings app on the Apple Watch itself with watchOS 6.
Swipe Up to Know Further Information.