AOL Mail on OS X 10.9.5

Can anyone give me step by step instructions on how to add back my AOL Mail account to my late 2011 mac pro running OS X 10.9.5. Problem is we stopping receiving mail on February 12, 2021. Unfortunately I deleted the mail account thinking I could just add back and fix problem, but it didn't.

If anyone suggests I must upgrade the OS, would need some instructions on that as well. Thanks