example:

sse.add("url", "https://example.com/sse")
   .init()
   .start((event) => {
       console.log("Connection opened:", event);
   })
   .accept((event) => {
       console.log("Message received:", event.data);
   })
   .error((event) => {
       console.error("Error occurred:", event);
   });

// Close the connection when no longer needed
// sse.close();