Export HighRise textures to UT4 map?

I am trying to export textures from the HighRise project into a UT4 map, but I am having some difficulty.
I tried exporting them but the td3 file was unknown when I tried to import.
I tried using migrate but then in the UT Editor, that new folder wouldn’t appear in the content browser.
I think copied the uassets manually and then they did appear in the content browser but when I tried to drag it onto geometry, it gave me that red circle with the line through it and it wouldnt apply the material.

What can I do?