How do I update to yahoo requested when I just signed on, will it update when I next sign on?
Starting January 31st, 2019, the classic version of Yahoo Mail that you’re using on your computer will no longer be available. To ensure continued access to your Yahoo Mail account, you will be automatically upgraded to the latest version of Yahoo Mail or Basic Mail, depending on the compatibility of your computer’s web browser.
it will happen, even if you don't want it
It will be automatic.