Hi @Aidil ,
At the moment Mobile Account is not yet available for TPG Mobile Application. We'll make announcement for any update related to this when it becomes available for now we encourage everyone to use our TPG My account section. ( https://www.tpg.com.au/myaccount ).
We also did an article that you may find helpful, this will help you add a mobile to the mobile service. Please see the link below.
How to add a data block to your TPG mobile service
Let us know should you require further assistance.
What apps can i use to topup and check my data? So confusing