Hello, I’m Virginia a fellow Windows user.
I’m sorry to hear that you’re experiencing problems.
Your only option is the use one of the backup codes shown during 2fa set up which should’ve been saved.
Otherwise there should be an option to choose ‘I don’t have any recovery options’ or similar wording & this should offer to send a code to an alternative email or phone number.
When you set up the app did you choose recover accounts or set up as new?
This is why I have the app on 2 devices so if I need to recover the app I still can authenticate on another device.