To work with payment services, you must start the Microsoft Dynamics NAV Server service with an Active Directory domain network account instead of with the Network Service account. If you have not set up a domain network account, then you will see the following error message:
Error Code=1020; Message = We encountered a problem resolving the host name. Contact your administrator if the problem persists.
You must assign write permissions to the Add-ins folder in the Microsoft Dynamics NAV Server installation folder for the user account that is used by the Microsoft Dynamics NAV Server instance. Also, you should restrict access to the folder for other users.