unfortunately there wouldn't be a way to recover your Google Account through your Samsung account.
You will need to go through the Google Account Recovery process to be able to recover your Google account to use it with your S20. Go to the Account Recovery page and follow those steps if you can with your computer.
If it's saved to Samsung Pass, once you're able to sign in, it should offer to insert. If you can't get to it, you will need to reset your Gmail password somehow. Can you try on a computer?