I used Direct Calling method to make a video call but cannot get audio and screen share functionality

I used Direct Calling method to make a video call but cannot get audio for both end user one & two.
Screen share functionality also not working
let callSettings = new CometChat.CallSettingsBuilder()

                                    .enableDefaultLayout(deafaultLayout)

                                    .setSessionID(sessionID)

                                    .setIsAudioOnlyCall(audioOnly)

                                    .showEndCallButton(true)

                                    .showScreenShareButton(true)

                                    .showMuteAudioButton(true)

                                    .showPauseVideoButton(true)

                                    .setCustomCSS(CSS)

                                    .build();

                                CometChat.startCall(

                                    callSettings,

                                    document.getElementById("callScreen"),

                                    new CometChat.OngoingCallListener({

                                        onUserListUpdated: userList => {

                                            console.log("user list:", userList);

                                        },

                                        onCallEnded: call => {

                                            console.log("Call ended:", call);

                                        },

                                        onError: error => {

                                            console.log("Error :", error);

                                        },

                                        onMediaDeviceListUpdated: deviceList => {

                                            console.log("Device List:", deviceList);

                                        },

                                    })

                                );

                            },

                            error => {

                                console.log("Call initialization failed with exception:", error);

                            }

                        );

                    },