post https://sandbox-api.onsched.com/setup/v1/locations//email/templates
Use this endpoint to a Create a Custom Email Template. You must convert the content to a base64 encoded string. Updates to the primary business location create company scoped custom templates. Updates to non-primary business locations create business location scoped custom templates. The master template cannot be updated with this endpoint.
The email template endpoints work a little differently than most. There are no endpoints to update the templates, we use the post endpoint to create a custom template instead. This endpoint creates a new email template that will be used instead. If you delete it, you are deleting the custom template you created and the original default template created by OnSched will be reactivated.