The API requires a service account with the ‘Log on as a service’ User Right assigned from your Domain Policy. Here’s an example showing the procession of AD tools to do this:
• Open the Group Policy Tool
•Right Click Default Domain Policy
•Select Edit
• Click on User Rights Assignment
•Double-click Log on as a service
•Click Add User or Group…
•Click Browse
• Enter part of the Account name to search for then click OK
• Select the matching name that you want. Our example uses WinBackup but you will have a more appropriate name
• Click OK to go back through all of the screens you opened to get here