Add a download button via TamperMonkey script or Firefox addon for content on specific website. -- 2

I frequent a website which offers great resources for free. The only issue with it is there is no way to easily save the content. I would like a TamperMonkey script (preferred) or Firefox addon which resolves the location of the resource and adds a download button next to the original button.

The site is built on top of React + Angular so you must be able to resolve JavaScript back to resource's URL!