It said that in the instructions…
You need the layer: “board” with the object “boardoutline”. this needs to be a single object. Layer: “silkscreen” is the top of the board and the Layer: “silkscreen0” is the bottom, Silkscreens can have as many objects as you would like.
<g id="board"> <path id="boardoutline"/> </g> <g id="silkscreen"> </g> <g id="silkscreen0"> </g>