Welcome 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 there has been a provisioning issue causing the service not to work, we'll raise this to our NBN Provisioning Team and have you contacted via email.
You may also contact them directly via chat https://www.tpg.com.au/chat/service-delivery