Wheeled robot unable to move with teleop twist keyboard + Odom frame in Rviz appears to be continuously moving up and down

Hi everybody!!! I am really in need of help as I am still quite new to ROS.

Right now, I am trying to simulate a robotic arm that has wheels in gazebo. I have done the URDF for the robot description, added the controllers in a yaml file, and created a launch file to load the robot in gazebo. The controller that I am using for my wheels is the velocity controller, and the gazebo plugin that I am using is the differential drive controller plugin.

However, here is the big problem, when I run the teleop twist keyboard python script in the terminal, my robot just can’t seem to move when I press the keys.

Furthermore, when I went on to Rviz to see if there is anything wrong/weird, I realised that the odom frame is continuously moving up and down, as if it is glitching. I am not sure if this is why my robot is not moving. If it isn’t is it there is a problem in my code?

*(Can someone let me know how to upload my codes here in this forum, I am not very sure how to do that)