why is my “turn on passcode” disabled on my apple watch?

Hi I_always_seem_to_need_help,

Thanks for coming to Apple Support Communities for help today.

Is the setting grayed out? If so there may be some restrictions on the paired iPhone or possible a managed profile if it belongs to a company or institution.

Was the Apple Watch set up for you by a family member with an iPhone? This may also explain the why the feature is disabled: Set up Apple Watch for a family member. The family member managing the Apple Watch would need to use the Apple Watch app to set that up.

If that doesn't explain it, let us know more details.

Have a fantastic day!