Export

Export a Python file from Maya, create a Control Rig in Unreal, then execute the exported script.
Export Control Rig
Creates a Python script that can be executed in Unreal to create an “Unreal-ControlRig” based on the current AdvancedSkeleton rig.

In Unreal, right-click the Skeletal Mesh object and choose “Create Control Rig”.
This creates a Control Rig object; make sure it is selected.
In the Unreal menu, choose “Execute Python Script” and choose the exported Python file.
Note: turning off “Auto Compile” makes the Python script run faster.