You can find the MPLS Diagnostics at Diagnostics → Routing → MPLS.
Here you have an overview of all VT AIR MPLS as well as LDP diagnostics They are all in the MPLS table that is shown here.
You can see the lables of each route, the Gateway it’s using and whether it’s using a gateway. The interface of the MPLS is shown as well.
To create your own MPLS routes please go to Routing → MPLS and refer to the documentation at MPLS.
Here you have an overview of all four different LDP diagnostics: