There isn't enough information there to help you, and what you did provide indicates that you want to register the Grandstream FXO device. If that's the case, and assuming you've installed FusionPBX correctly, do the following:
- Create an extension. After saving it, write down the extension number and password.
- Log into your Grandstream FXO device, add the account to the device using the extension number, domain/realm (this may be the IP address of your FusionPBX server), and password belonging to the extension you just created.
That's a general idea, anyway. You may need to look up how to add the account to the Grandstream device from Grandstream. Grandstream is pretty good about providing instructions for their devices on their website.
To create an outgoing gateway, you'll need to create the gateway based on the information provided by your termination carrier on FusionPBX by following the instructions:
https://docs.fusionpbx.com/en/latest/accounts/gateways.html
Then, you'll want to create an outbound route so calls will be routed to the correct gateway.
https://docs.fusionpbx.com/en/latest/dialplan/outbound_routes.html
I hope this helps.