@frontier thank you for your suggestion. It took me a while to get it work fine but finally I chose to install the plugin through NPM, import it with ES6 import where I needed it and bundle it all together using webpack (also installed with NPM).
Despite of this, I like your suggestion of having the plugin files saved in local because it seems an avoid-possible-future-problems option.
I had other troubles when trying to use the plugin in my app, so maybe this other question is useful for others.