I can add some text it looks like, but this example below does not end up sending the message

var tb = document.querySelector('.markup-2BOw-j.slateTextArea-1Mkdgw ');

if (tb) {
    var msg = "Time is nearly up";
    var int = 3000;

    function send() {
        tb.innerHTML = msg;

        const ke = new KeyboardEvent('keydown', {
            bubbles: true,
            cancelable: true,
            keyCode: 13
        });

        document.body.dispatchEvent(ke);
  }

  setInterval(send, int);

}

Is there a way to have it send the message to the chat?