I actually have a server which I could use for this purpose. Could you highlight how this could be achieved? Thanks!

Thanks for your answer! I understood some of the things you said but, for access control in particular, you're saying that I can restrict the API call to my website only? How could I do that from a simple HTML block in wordpress?

Thank you for your suggestion. It lead to learn how to read the console after publishing the website and as a consequence lead me to the error message saying the connection should be https. Added an "s" after the link and it worked!

Although I'm not aware of how to print the information coming from the $.getJSON part, so I don't know if it's actually fetching the data properly.

Thanks for your comment! Yes it does. It's supposed to be a fully functioning sample of the code, original from Apex Charts the documentation.