Invoke-SwisVerb - Access Denied

I was advised by SolarWinds support to post a question on the community forms.  I am trying to run the below command and receive access is denied errors.  The account is a full admin on the server and in the IPAM application.  Any help would be greatly appreciated.

'Invoke-SwisVerb $swis IPAM.SubnetManagement GetFirstAvailableIp @("10.99.99.0", "24")'.