Welcome to the community!
If you're having issues with NBN service, we recommend the best thing to do first is check if there's an outage on the NBN network.
We have created this article that can guide you on How to Check for NBN Network Outage
If there are no known outages in your area you may perform basic troubleshooting, we did an article that you may find helpful see this link below.
In this particular case, we've seen that the service is installation is not yet complete, based on the latest update NBN Co. will send an NBN Technician to close the service installation.
We did an article that you may find helpful, this will guide you on how to track your NBN service installation. How to track your TPG service installation
Once the NBN service installation is complete you may proceed on setting up the equipment or the modem/router. You may check this guide.
Further updates will be provided by our NBN Provisioning Team, should you need further assistance, feel free to reply to this message or chat with us at https://www.tpg.com.au/support/contact/ and we'd be glad to assist you.