Calendar and Contacts from att.net on iPad

Recently I had to reset my att.net access on my PC using Outlook by getting a secure key.  That took some time to figure out by eventually get Outlook working again.  Access to my att.net email from my iPhone was unchanged and continues to work for email, calendar and contacts.  However had unfortunately deleted by att.net email account from my iPad.  I was able to set it up again using the secure key.  However I no longer see any of my contacts or calendar from att.net.  When I add an Mail account, the only choices are "Mail" and "Notes".  I cannot get Contacts, Calendar, Reminders or Notes to come up for a new account.  I have an older iPad which does show att.net email, calendar and contacts.  I appears it's getting the Calendar from a Yahoo server.  Long story but any ideas for adding my calendar and contacts from att.net to my iPad (10.5 Pro) would be appreciated.