How are licenses applied to javascript libraries?

Question

JavaScript

Take for example - jvectormap.com/licenses-and-pricing (example - because I needed it)
Can I use it on my site for free or not?
When using the GPL for desktops - everything is clear, the code is compiled and you need to attach the source codes.
But regarding js... Formally, whenever a user enters the site, he receives the source code of the entire application - whether I want it or not. Means I deliver application with the source codes. And why would anyone buy a license at all, if even support is not promised in the conditions?

Answer 1

To use the GNU GPL libraries, your project must also have a compatible license. That is, your project must be licensed under the GPL anyway. Even if you imagine for a second that the frontend is already open source because anyone can watch and download (although this is not true since there is minification / aglation and a bunch of other things that make it difficult for other people to change the code), then you still need to have it under a compatible license with the GPL. Then the backend will have to be released under this license, because the proprietary license only works with the LGPL.
So it turns out that if you used the GPL version of the library, you will have to put the entire application on github in its entirety.