This example has a couple quirks, but it gets most of the way there.
https://anvil.works/build#clone:BVXPHRNO7XGIPMGK=C2MWUSWT3V776PL5GK4LMJQJ
Step 1) Add a column panel to the main form
Step 2) Create a new form with custom HTML
Step 3) Use the code you want for a D3 visualization (confession: I was hit-and-miss getting these to work): Gallery · d3/d3 Wiki · GitHub
Step 4) Insert the code into the customHTML for the new form
Step 5) For some reason I am having trouble loading scripts from cloudflare/etc. from within a form. Hard-coding it into the space between
<script type="text/javascript"> (paste a billion lines here) </script>
is hackish but seems to work
Step 6) Create an instance of the new form object and add it as a component to the column panel:
self.column_panel_1.clear()
d3Object = D3JSForm()
self.column_panel_1.add_component(d3Object)