How do I use the mail app with aol account
My parents have an iMac late 2013 running OS High Sierra 10.13.6 and I can't get my fathers email to work anymore by using the mail app. I can get it to work on my laptop running Big Sur but when I try to create a new internet account to access mail it doesn't recognize his info. The one difference when creating the internet account on the different OS's is that the High Sierra ask for name whereas Big Sur just ask for email and password. Any help would be greatly appreciated. Thanks in advance.
Jack
iMac 21.5″, macOS 10.14