On the topic of generating QR codes with JavaScript, I have a project that requires generating QR codes and the various libraries I could find all seemed to be rather... poor. A lot of them were simply made for another era of JavaScript, where the only way to generate the image was to set up a table, or even implement its own png encoder(?). There were a few more modern ones, with active development, but the changelogs weren't terrible re-assuring as they were mostly fixing bugs that really shouldn't happen in a standards compliant code generator.
In the end I settled on Project Nayuki's QR code library[0]. The JavaScript is targeting ECMAScript 5, but is commented really well so it's not too difficult to refactor it into ES6+. I'm hoping to publish my efforts soon, but it still needs some more work.