I cannot access icloud.com emails on microsoft outlook

Since you are using a 3rd party e-mail program, you need to enable 2 Factor Authentication and use an app specific password to access iCloud e-mails. Apple made that a requirement.

Apple ID -Two-factor authentication

Two Factor Authentification availability

Apple ID - Using app-specific passwords

Apple ID - Two Step Verification App Specific Passwords

Apple ID - Two Step Verifications FAQ

The iCloud account. I'm not familiar with IOS Outlook, so the following may not apply. Try Settings/Accounts & Passwords to add the app specific password. Then test. If that doesn't work, then go back, delete the account and add it back.

You are welcome. Try creating an app specific password for the account. Then delete the account and add it back using the app specific password when setting the account up.