How to use draw.io hyperlink to address local files

The links that Google provide to publicly visible files aren't actually the raw file, they are a link to a Google page that has an indirection to that file.

In order to get the raw file the file must be placed in a publicly visible folder, being public on its own isn't enough.

Next, Google decided to remove your ability to get the raw URL of the file in the new Drive UI. You need to click on the cog top right and select "Leave the new Drive". In the old Drive UI select the file, then the "Details" panel on the right:

You'll then get the raw URL under "HOSTING":

That's the URL to paste into "Public URL of the diagram"

Obviously, Google seem to be wanting to remove public file raw URLs, we are thinking about an alternative to this when they remove the old Drive UI completely.

With the shape you mentioned: select the checked sub-shape and paste it where you want it (replace the empty rectangle) or use a different shape which can be manipulated via style (create a simple rectangle then copy the following text into its style): "shape=mxgraph.mockup.forms.checkboxGroup;mainText=+Option 1,Option 2,Option 3,Option 4;textSize=10;textColor=#dddddd;fontColor=#666666;"

The "Option n" text can be whatever you want and add a "+" whick you want to be checked. You can also add or remove entries to the mainText list. The other parameters should be obvious. If you want further help, just ask.

The same applies to radio buttons, just use the "mxgraph.mockup.forms.radioGroup" shape.