In the case of TPA Wallet, your access is with your phone number and registered email, so you must have access to these two items to proceed.
Once you recover your access to Stage Meta Account, you will be able to locate your Private Key following these steps:
Connect to Stage Meta using TPA Wallet.
On the top right corner, go to "View Panel" under your Account Name.
On the menu options, go to "TPA Wallet".
Your Private Key is available for export in this option, on the bottom of the page.
Remember to always keep your private key safe.