I started working on Ros. I am using noetic and ubuntu 20.04. I created a model in gazebo, a simple 4 wheel cart, in gazebo model editor. I added keyboard controls to control the motion of the bot. i created a workspace, made packages and added the required .sdf, .yaml, .config, .launch, .world and .py files and used catkin build and sourced the files. When I used 'roslaunch fourwheelbot model.launch' (fourwheelbot - name of the package, model.launch - launch file), it is displaying a different model, some pre-built model present in the gazebo library. I can't figure out the problem. I tried using chatgpt but it didn't help much.