I can’t add my outlook account in my iPad. Whenever I try to add the account I get the message “unable to verify account” immediately

Are you attempting to install the Outlook App - or are you adding your Outlook email account to the native Mail App?

In common with many other Mail providers, Microsoft Outlook and Hotmail accounts now use App Specific Passwords to access IMAP or POP3 mailboxes.

The Mail App on each of your devices, such as your iPad, requires a unique password to be generated from within the Microsoft account. To do so, you’ll need to sign-in to your Microsoft account from a we-browser. Note that the system generated App Specific password will intentionally differ from your Microsoft account password - and can only be used to access your Microsoft mail.

More information about Microsoft’s App Specific Passwords can be found here:

https://support.microsoft.com/en-us/account-billing/using-app-passwords-with-apps-that-don-t-support-two-step-verification-5896ed9b-4263-e681-128a-a6f2979a7944