Pythreejs Texture UV Mapping

Question

I am not able to apply UV mapping to custom meshes in pythreejs. Here is what I am trying:

import pythreejs

material = pythreejs.MeshPhongMaterial(
    map=pythreejs.ImageTexture(imageUri="out/2ndAvePh_big.png")
)
triangle_geometry = pythreejs.Geometry(
    vertices=[[-1, -1, 0], [-1, 1, 0], [1, -1, 0]],
    faces=[[0, 2, 1, None, [], 2]],
    faceVertexUvs=[[[0, 0], [1, 0], [0, 1]]],  # I think this is how I'm supposed to set this
)
triangle_mesh = pythreejs.Mesh(triangle_geometry, material)

The mesh doesn't get the texture applied to it. It looks like it gets a solid color for one of the pixels in the image (whether or not faceVertexUvs is set...).

I can apply the same texture to a simple box and it works but I can't set UV mapping for BoxGeometry:

box_geometry = pythreejs.BoxGeometry()
box_mesh = pythreejs.Mesh(box_geometry, material)

What am I doing wrong here?