Error "This feature is not available for your plan"

Problem statement

The below error is received from a Management API call:

This feature is not available for your plan. To create or modify prompt templates, please upgrade your account to a Professional or Enterprise plan.

Cause

The customer has an Enterprise account, but their current contract is not attached to the tenant.

Solution

The customer has to send an email to tam@auth0.com and request to add the tenant to their contract.