If you're actually concerned about your data, find an offline QR generator. Encoding a WiFi network is just adding some extra plaintext to a normal QR code.
One explanation is here:
https://pocketables.com/2022/01/how-to-format-that-wifi-qr-c...
One explanation is here:
https://pocketables.com/2022/01/how-to-format-that-wifi-qr-c...
https://f-droid.org/en/packages/com.secuso.privacyFriendlyCo...