Share screen is not working

Hi guys, I am new with Jitsi, i think is great to add to my web page, but i have some questions:

  1. I saw some examples code, but some of them is “iframe” and others use “script”, I used both in a page and i get two jitsi conference room open, i think i should use only one option. What is the correct way to used?
  2. Screen Sharing is not working, I got the following message: “Screen sharing extension failed to install”, please could advise? I try it with iframe and script. This is my code:
    “script”
    var userName = ‘Wester’;
    var meetingRoomName = ‘RoomGrupo’;
    // Call APi an dget full user details here
    var domain = “meet.jit.si”;
    var options = {
    roomName: meetingRoomName,
    width: “100%”,
    height: 680,
    parent: undefined,
    configOverwrite: {},
    interfaceConfigOverwrite: {
    filmStripOnly: false
    }
    }
    var api = new JitsiMeetExternalAPI(domain, options);
    api.executeCommand(‘displayName’, userName);
    “/script”
    I am using Firefox.
    thanks in advance