rtmjoin.js

joinbtn.addEventListener("click", ()=>{
//join a channel
const channel = client.createChannel(chid.value); //pass your channel ID
channel.join().then(() => {
  /* Your code for handling the event of a join-channel success. */
  console.log('Channel joined!');
}).catch(error => {
  /* Your code for handling the event of a join-channel failure. */
  console.log('Channel join failed.');
});
flag = true;