I don't agree with the previous answer, using a GPLv3 library does not make your website GPL, if you merely include the library in its compiled form provided by the author and exported to the
window namespace. Then it's the same as using a precompiled binary in other programs, and using "sockets, pipes and command line interface to communicate with it"
By contrast, pipes, sockets and command-line arguments are communication mechanisms normally used between two separate programs. So when they are used for communication, the modules normally are separate programs. But if the semantics of the communication are intimate enough, exchanging complex internal data structures, that too could be a basis to consider the two parts as combined into a larger program. https://www.gnu.org/licenses/gpl-faq.en.html#MereAggregation
On the other hand, if have a source code that imports the library, and then compile it with something like Webpack, you're producing a derivative combined work using static linking and must release all JS source code for the website.
Where's the line between two separate programs, and one program with two parts? This is a legal question, which ultimately judges will decide.
I think you have to make a call here, for example if you're using callbacks, that's quite intricate communication, whereas if you're merely passing args in a config object, that's almost the same as command line arguments.
You can ask the author of the library what he meant by GPL as well. For example, the WOW https://github.com/matthieua/WOW lib specifically provides a dual license, one for commercial use, and one for derivative open source work. I still don't think that because they released the code under GPL, I would have to make a non-commercial website open source if I used their library.