Ok, now I want to add a Drawing Canvas image to my Json object to download with all my other data as one file.
I think it should be done using the Binary object, but it's like figuring out a black box.
And all I'm getting from examples is a blob url:
blob:https://preview.construct.net/7643aa83-b9f2-4d2e-a3c6-9fe9e02e0844
Which doesn't seem like it would be the right thing, but I have no idea how to even test if that data is what I need.