Why do I get the error, "[XYZ] is not enabled for this subscribe key"?

This error occurs if you attempt to invoke APIs that require an add-on feature to be enabled on your key set, for example:

• history requires the Message Persistence add-on
• channel groups requires the Stream Controller add-on
• hereNow requires the Presence add-on

To resolve, simply enable the add-on feature that is referenced in the error for your key.