Using Account Key, you will no longer need to enter any password and can do it simply with a tap on your verified phone. After you’ll enable Account Key for your account, you’ll receive a notification on your preferred mobile device every time you try to sign into your account and this way you can sign in with total ease. https://www.customersupportuk.co.uk/yahoo-customer-care-number.html

1. Yahoo Customer Support UK

2. How To Set Up Yahoo Account Key To Sign In?
Find it hard to remember multiple passwords for multiple
accounts? Well, we can’t do anything about your any other
account but can make it easy to sign in from your Yahoo
Account. Want to know how? Yes, you got it right, we are here
talking about the Yahoo Account Key Feature by which you
won’t need to remember any password to sign into your
account. Using Account Key, you will no longer need to enter any
password and can do it simply with a tap on your verified phone.
After you’ll enable Account Key for your account, you’ll receive a
notification on your preferred mobile device every time you try
to sign into your account and this way you can sign in with total
ease

3. • First, make sure you have any of the Yahoo App installed on
your mobile device and is signed in to it.
• Now you need to enable account key feature from your web
browser. To do so first go to Yahoo Account Security page.
• Select See How It Works option and then select your device
and Yahoo app on which you want to receive a notification.
• To receive a notification on your phone, select Send Me a
Notification.
• Now tap on the Approve icon on your mobile device.

5. • Again in your web browser, select Always use Yahoo
Account Key option.
• Verify your mobile phone number to sign in a case when
you lose access to your device.
• Now in order to sign in to Yahoo Account using Account key
first go to Yahoo Sign in Page and then enter your Yahoo ID.
• After you’ll click Next you’ll receive a notification on your
mobile.
• Now on your bile device tap on the receive notification or
open the Account Key enabled Yahoo App.
• Select the Account Key icon and then tap on Approve.

6. That’s all. We hope you found these steps easy enough for your
understanding and are being successfully able to set up account
key for your Yahoo Account. However, still, if you need help
regarding your Yahoo Account feel free to contact Yahoo
Customer Care UK @ +44-20-31292909 and get the best support
possible right away.
Source
Also, Read This Blog: How to retrieve your Yahoo Mail?