Openni2 and gmapping could not detect astra pro camera

Hi,

i am new to ROS and turtlebot. i am using astra pro camera with turtlebot. i want to use gmapping module of turtlebot for SLAM. when i run following command

$roslaunch openni2_launch openni2.launch
then i get following error message

[ INFO] [1567273191.219997236]: Initializing nodelet with 4 worker threads.
[ INFO] [1567273192.870371799]: No matching device found… waiting for devices. Reason: std::string openni2_wrapper::OpenNI2Driver::resolveDeviceURI(const string&) @ /tmp/binarydeb/ros-indigo-openni2-camera-0.4.2/src/openni2_driver.cpp @ 737 : Invalid device number 1, there are 0 devices connected.

and when i run following command
$roslaunch turtlebot_navigation gmapping_demo.launch
then i get following error
process[move_base-14]: started with pid [4270]
[ INFO] [1567273763.430017088]: No matching device found… waiting for devices. Reason: std::string openni2_wrapper::OpenNI2Driver::resolveDeviceURI(const string&) @ /tmp/binarydeb/ros-indigo-openni2-camera-0.4.2/src/openni2_driver.cpp @ 737 : Invalid device number 1, there are 0 devices connected.

please help me .