Have to tried to contact their support , might be they can disable it for you.
I am using Chrome. I have used Chrome for a very long time to access Yahoo email and have paid to have an ad free account that I can use with a client if I choose. I prefer the web based.
Over the past several days, when sending an email, I get an intermittent annoying pop up. I tells me to install the free Yahoo mail app that can notify me when someone receives my email. I am not interested in the app, but it keeps popping up randomly on my screen after I click send. I guess since I have Win 10, it assumes I might be interested in the app. I CAN'T MAKE IT STOP!
Sheesh, I pay these people and they still annoy me. Any suggestions? Getting hold of Yahoo is very difficult.