@Francesco Gaetani Most browser offered for use as the "built in" browser "app" in most smart TV's (including LG), are very basic, do not contain all the features and goodies that are in mainstream PC browsers (like Firefox, and Edge etc). So, you will find many things that do not work, and many items that will not load or play. The other issue is that the browser apps RARELY get updated on smart TV's, so often fall very behind current browser technologies.
Because smart TV's have a browser, and "apps" many owners think they are like a PC, but it is like comparing chalk and cheese.
It my sound very "clunky" but your best method is to use you laptop, and cast the video to your TV.