Ld19 Hector_slam

Hi, I recently purchased the LiDAR ld19, and following your instructions . I was able to display the laser in rviz through the command

roslaunch ldlidar_stl_ros viewer_ld19_noetic.launch

after installing hector_slam i run the command rostopic echo /tf

and i get this screen

I have tried various things but I can’t see the lidar in the default map of hector. Can someone help me please?