Thank you for your reply. I do have Vsphere Web Client 5.5. Does this matter?
I tried both of the commands separately, but Firefox told me it couldn't find the address:
https://localhost:9443/admin-app
https://127.0.0.1:9443/admin-app
I have not changed the port from the default, so it should be 9443, as that is the port I use to get to the web client.