Hi Arnold,
I believe you are using Gluu 4.1 as mentioned in the ticket. Starting with version 4.1, oxd is offered as one of the several components of the Gluu Server CE. So instead of installing oxd on localhost please install oxd along with the Gluu server.
Refer: https://www.gluu.org/docs/oxd/4.1/install/#installation-via-linux-packages
After successful installation, you should be able to access oxd using URL: https://gluu.a2g.nl:8443/health-check (where `gluu.a2g.nl` is your op_host and oxd-server is running on port 8443)
So, on `Site registration` screen of oxd-java-sample application `oxd server host` will be `gluu.a2g.nl`
and `oxd server port`: 8443
I think the above approach should work for you. Please let us know if have any concerns or facing any error.
Regards,
Arnab