Do I have to backup every time my Wallet updates?

No, you don't. After any updates, your wallet will continuously backup. So you can use your wallet as normally.

Coin98 Super App doesn’t change users’ Private key and Passphrase after updating.

You only need to back up your Private key and Passphrase once. We recommend that you do this as soon as you create a new wallet.

You can access your wallet at any time as long as you keep your Private key and Passphrase.