iOS -How to add an email account to an iPhone
Click Settings on your iPhone.
Click Passwords and Accounts.
Click Add Account.
Click Microsoft Exchange.
Enter your Email, change the description (optional), then click Next.
Click Sign In.
Enter your email, password, then click Sign In.
You’ll be redirected to the Duo app. Use your preferred method of authentication.
Click Continue.
Choose the options you’d like to turn on or off, then click Save.