@Medikaloka_Hermina
I think the code that handles asynchronous processing is weird.
If you proceed with the following code, you can check that it works normally.
SendBirdCall.connectWebSocket().then(result => console.log(result)).catch(error=>console.error(error))
or
SendBirdCall.connectWebSocket()
.then(function(){
console.log("success");
})
.catch(function(error){
console.log("error");
});