Load xodr in UEeditor without fbx

[Sephiroth1118]

Hi!
I'm now working on a project that needs to create a map in Carla which should contains buildings. The standalone mode doesn't meet the requirement and I do not have the license of Roadrunner. What I'm trying to do is load the xodr file inUEeditor as a bare map like in standalone mode and then add some buildings manually. But I found make import do not work for xodr file only. Is there anyway to store the bare map in standalone mode as umap so that I can edit it in UEeditor?
Thank you so much!