Then you are not doing something right. Please follow the guide here step-by-step:
Once you get to the Outlook Scopes field replace the default value with this: offline_access https://outlook.office.com/IMAP.AccessAsUser.All https://outlook.office.com/POP.AccessAsUser.All https://outlook.office.com/SMTP.Send
Then when you submit the popup and go to microsoft, you login as the email you are configuring in osTicket. Then you consent to the permissions and you should be good. If you have to request consent from an admin this will not work. Your admin will need to consent on behalf of the org in the enterprise applications or allow users to consent themselves.
Cheers.