You need to register for a Telstra account and be logged into your MyTelstra app.
In the app, ensure you're logged in with your Telstra ID and connected to Wi-Fi.
Then go to the 'Services' tab and select your mobile number. Scroll down and select 'Transfer or restore eSIM' and follow the steps on screen.
I am Absolutely elated with this. I decided to share it because I have been religiously trying to get an eSIM ever since I got my new phone and Telstra kept saying they've migrated to a new system and Esim on prepaid is unavailable. Tonight it worked!
Enjoy!
Kind regards
Yes, they started this (I think) about a month ago. Still waiting on eSIM for their upfront plans though