Hi Afri,
This error occurs if you have not assigned the appropriate license to the user email address.
Visit admin center -> active users -> search the name -> select user -> go to licenses and ensure the user has Office 365 F3 or Business Standard or any other appropriate licenses. After applying the license, wait for some time before logging back in to Outlook.
If this is a personal email, check that you bought the appropriate license that includes Outlook.
Here are more resources on Licensing Options
https://learn.microsoft.com/en-us/microsoft-365-apps/outlook/get-started/licensing-options
I hope it helps
Teddy