Can't make Chartkick library to function using this example

Ii have this page https://github.com/buren/chartkick-phoenix-example/blob/master/web/templates/page/index.html.eex exactly and the view for it and the Chartkick library installed. I cannot get this library to work.

Start by comparing the installed application with web/templates/page/index.html.eex from the linked chartkick-phoenix-example page and inspect the corresponding view. Reproduce the reported failure and identify the missing setup or error; done means the example page renders its chart successfully.

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