MPLS MTU and BRIDGE and CRS

RouterOS Forwarding Protocols
1

Hello.
I have this topology:
sch1.png
I cannot connect MPLS between RB1 and RB2 and CCR.
CRS have all switched ports.

  1. Must I enable MPLS also on CRS?
  2. CCR Mpls Interfaces are ETh1 and ETh2 or BRIDGE?

THanks