Mattermost Integration with Splunk Soar Phantom

Has anyone gotten Splunk Soar Phantom to work with Mattermost?

We created a bot account to work with Splunk Phantom, filled out all the fields in Phantom with the token ID etc, but still get the following error message on ‘Test Connection’

Exception Occurred. argument 1 must be str, not None Traceback (most recent call last): File "../pylib/phantom/", line 2372, in _handle_action File "../pylib/phantom/", line 925, in _validate_config File "../pylib/phantom/", line 642, in _decrypt_dict_key TypeError: argument 1 must be str, not None

(asking same question in Splunk Phantom Community as well since I’m not sure on which side the error occurs)