Hoffe mal auf das BesteGreetings
If there's something unusual about your sign in or recent activity, you may be asked go through a second verification step, even after entering the correct password. This may happen whether you have two-step verification enabled or not. We do this to protect accounts from unauthorized access. Read more about this in the following article.
Account verification prompt at sign-in - https://help.yahoo.com/kb/mail-for-desktop/account-verification-prompt-sign-in-sln22500.html
Yahoo no longer provides direct support via phone or email address for their free Yahoo accounts. With over 300 million accounts the account recovery process is now completely automated. Yahoo determines you are the rightful owner of the account by sending the account key code message to the verified phone number or email address entered on the Account Security page for this account. If this information is outdated, was entered incorrectly, or was never set up then it's unlikely you will be able to recover this account.
Start by going through the Sign-in helper mentioned in the following article from a laptop or a desktop.
Problems signing in to your Yahoo account -
https://help.yahoo.com/kb/learn-fix-problems-password-yahoo-sln2051.html
When you go through the account recovery process and you see account recovery options that are no longer available you need to choose "I don't have access to this phone" or "I don't have access to this email" to see what other account recovery options are available. If you get the "Uh oh" message saying the account can't be recovered online you can go through the steps below to see what other account recovery options are available.
Start here at Help for Yahoo Account - https://help.yahoo.com/kb/account
Scroll down the page until you see a "Contact Us" button.
Click on this to open a page that says "Need assistance with a Yahoo product? Let's see how we can help.".
Under "Tell us your Yahoo email address and product." you select the product you want help with. In this case it would be "Account".
Enter your email address and check "I'm not a robot". You may be sent to another CAPTCHA page for additional proof.
Click the "Get started" button
This opens the "CHOOSE SUPPORT OPTION" page.
If you see the option "Contact a Yahoo specialist" then you can get live chat support for this issue. If the chat line is closed you can submit a support ticket by clicking on "Email a Yahoo specialist". Please note that live chat support is very limited in both availability and the scope of the issues it can address..
If you have gotten this far and haven't been able to recover your account then I'm sorry but there are no other account recovery options available.