Email app not working after ATT changed my email account password to a mail key

ATT support person had me change the password to a mail key in the settings at Att.net. They did not have me change the settings on my IPAD. It did change it in Passwords &Accounts. Under accounts I only now have ICloud and Yahoo. If I need to add a new account for Apple Mail do I need a IMAP Mail key like I used for Yahoo instead of a password? Thank you. You sound very knowledgeable. I hope you can help. I miss using the Mail app on my IPAD.

ATT support person Had me change the password tp a Mail key in the at att.net. They did not have me change the settings on my IPAD. It did change it in Passwords & Accounts. In accounts I now only have ICloud and Yahoo. If I need to add a new account for Apple Mail do I need a IMAP Mail key like I used for Yahoo instead of a password? Thank you. You sound very knowledgeable. I hope you can help. I miss using my Apple email app.