Sign in with Email not possible

I’m trying to log in with the option “sign in with email”. In the next step I enter the mail address and click “next”. Then a message appears, that tells me " Sign in

You already have an account

You’ve already used
Sign in with Facebook to continue.".

I can log in with Google, but this account does not have the Tourer subscription.
So I need to login with my other account, but it does not allow me to continue.
Because I have no Facebook Account any longer, also this way is no option for me to log in.

What can I do?

Why is it not possible to log in with my email address?
Obviously my email address is well known by Kurviger, but the message that I get displayed seems to belong to a registration process, rather than a log in.

Please wait until @boldtrn who manages the website can see your question and answer.

I replied to the email you send earlier as this also contains your actual email address.

The problem is security. We use default security procedures to allow access to your account. You can only log in with the means you authorized Kurviger.

If you want to add an email login to your account, you need to sign in first with your existing login option, then you can add an email login. If you deleted your Facebook account that is not possible anymore.