Create an image of a chart (nodered)

As i wrote in the title i need to create the image of some charts to add them in a single pdf.For this purpose chart-image plugin would be perfect but unfortunatly i 've tried for ages all the different solutions but i can't manage to install it ( i have installed several others plugins), so i was wondering if somebody could give me some solutions/ideas to do it. If this could help at the moment i'm able to draw the real time graph with template nodes, however i don't know if it's possible to extract an image from it.