To enable GetAccept Flow Template "GA0006: On Doc Remaining in Reviewed status", a Salesforce admin needs to follow a few additional steps that are not required for GetAccepts other Flow Templates.
Note: To be able to enable this GetAccept Template, you should first have a "Default Workflow User" specified in the "Process Automation Settings" under Setup.

The steps to enable this Flow Template are as follows:
Enter Salesforce Setup.
Click or search for the "Flows" page.
A list of available Flows will appear.
Click the "GA0006: On Doc Remaining in Reviewed status" flow.
On the right hand corner of the screen, click"Save As" to create a duplicate of the flow.
Enter a name for the duplicated flow.
Click "Add Scheduled Paths" in the newly created flow.
Enter a Path Label
Select "GetAccept__GetAccept_Document__c: Last Modified Date" as Time Source
Select number of days or hours desired for when follow up task should be created in "offset number" field.
Select "Days After" or "Hours After" for "Offset Options field".

For more information on GetAccept Salesforce Flow Templates you may also refer to the following article:
http://help.getaccept.com/en/articles/5085558-adding-a-getaccept-flow-template-in-salesforce