There are many versions of PowerShell scripts to report SharePoint external users online. Most don’t handle team-connected sites, so we take the time to explain the oddities of the Get-SPOExternalUser cmdlet and create some data that we can report using the PSWriteHTML module. All in day’s work with Microsoft 365.
https://office365itpros.com/2022/07/20/sharepoint-external-users-report/
