Hi @Kerwin Rean Kallego I saw you figured out a solution! For others, you could do it this way too:
$guestUsers = Get-AzADUser -UserType Guest
foreach ($user in $guestUsers) {
//dosomething $user.DisplayName
}
Please let me know if you have any questions and I can help you further.
If this answer helps you please mark "Accept Answer" so other users can reference it.
Thank you,
James