First of all, you need to enter in the Yahoo mail Login. 1-877-749-5444 Then you have to click on the gear logo in the upper right corner of the Yahoo mail screen. After that, you need to tap on the settings & new lightbox windows will be opened. Also, you have to check the mail version & change it to basic at the bottom.
https://www.monktech.net/yahoo-mail-login.html