Thank you for reaching out to us.
You should be able to see all the labels configured in Security Compliance Center (SCC) in Outlook as well Office apps as per the configuration you defined in SCC.
Do you have the Outlook with latest binaries, reference https://learn.microsoft.com/en-us/microsoft-365/compliance/sensitivity-labels-office-apps?view=o365-worldwide#:~:text=Sensitivity%20label%20capabilities%20in%20Outlook
Assign Permissions now & Let users assign permissions are encryption settings, reference https://learn.microsoft.com/en-us/microsoft-365/compliance/encryption-sensitivity-labels?view=o365-worldwide#:~:text=their%20original%20encryption.-,Configure%20encryption%20settings,-When%20you%20select
If you still have any questions, let me know.