If you uninstall your app with 2FA enabled, you will no longer be able to sign transactions in this account as you won’t have the Hardware Signer private key.
Thus, if you want to uninstall your app, you should first go back to Seed Signer (in Account Settings -> Security Settings) and only then uninstall your app.
If you already uninstalled your app, then you lost access to the Hardware Signer and the only thing you can do is to issue a ‘Request to Remove Hardware Singer’ that will be executed with a 4-day time delay.
