Chat on ASP.NET Core + SignalR - how to connect it to another site with a script?

Question

JavaScript

I am writing a chat that should connect to a page of a site using a script.
I use ASP.NET Core MVC + SignalR.
I can’t imagine how to implement such an application, just its very connection to another site.
Tell me please.

Answer 1

In fact, you are doing SaaS.
That is, you should have:
That's all.