How to link Valve Index controllers

Hello, I tried to use Unreal Engine 4.23 in order to do some architecture vizualization. Workflow followed : 3D model created into Revit then in 3DS Max, export and import datasmith file into Unreal (a blank project), add VR template (Motion Controller Pawn and BP Motion Controller). When I start to play the level we can see the building (360°) but we don’t have our controllers. I tried several settings but it doesn’t work at all. Could you please help me with this issue and indicate me the process to follow in order to link my controllers ? Sincerely,