1. Tap Settings.
  2. iPhone Settings Icon
  3. Tap Accounts & Passwords.
  4. Image result for ios 12 passwords and accounts
  5. Tap Add Account…
  6. iPhone Add Account
  7. Tap Microsoft Exchange.
  8. iPhone Add Exchange
  9. Enter the following information:

    1. Email: <<Your Email Address>>

    2. Password: <<Your Password>>

    3. Description: Office 365

  10. Tap Next.
  11. On the Settings screen, select the items that you’d like to have synced to your iOS device. Tap Save.
  12. iPhone Microsoft Exchange Settings