documentGenerator API "Requires Admin Access" error

I am calling the documentGenerator API from a commerce transaction via an action button. The action button calls a commerce Library Function,

The call returns the Error-Message of "This action requires admin access". If I run the action it works fine because I am an admin but when users run it they get the admin access error.

I call other API's from commerce processes using similar logic and those work fine. Why would the documentGenerator require admin access?

It appears to work in our test environment but not production. Both environments are Version: 25B Patch 5

This is the code I am using....