afni.nimh.nih.gov

Great you worked it out - a few ways. Just to add some more options, other Xservers on Windows will probably work too. I've tried MobaXterm that combines an X11 server with a configurable terminal also works pretty well. That can start the WSL Ubuntu inside the application, so it may be easier. Others may be good too - Xwin32, Exceed3D, X410, but these others are not freeware.