Error Submitting Updateable Tax Forms

We are on HCM 9.2 – Tools 8.55.19 and have implemented the
Updateable Tax forms on our fluid tile in an ESS sandbox.

We can access and open the forms but are prompted to enter
login credentials, which are not accepted and once the login box is cancelled,
the error message: “An error occurred during the submit process. Authorization
is required for this network service.” and an additional message of: "The server XXXX.com is asking for your user name and
password. The server reports that it is from PeopleSoft Enterprise PeopleTools." (XXXX - denotes our internal server name)

I imaging this is a security setting, but I cannot find it.