A developer in our organization has a console application that is exporting data into PDFs on one system, and then is uploading to a SharePoint Online document library. This works well, but the developer is using their account to authenticate.
Is there any type of 'service' account? We were told that resource accounts could possibly work, but that does not seem to be the case.
Or does this account need to be a paid-for licensed account that has permission to the team site?
It appears that a lot of Microsoft's documentation covers how to use the API, and you must authenticate, but not many more details that we have found on the limitations there.
Update: We are using ADFS, and do not have Azure AD.