Modifying robot.xml file to add sphere at end-effector to visualize trajectory

[ByeongGyu-Kim]

I am using robosuite 1.4.0, and I want to visualize the end-effector's trajectory by rendering a sphere at its position, like drawing a path. However, the sphere I added in the XML file does not appear when I render it.
I added the following geometry inside the end-effector (EEF) body:

<inertial pos="0 0 0" mass="0.5" diaginertia="0.05 0.05 0.05" />
<!-- This camera points out from the eef. -->
<camera mode="fixed" name="eye_in_hand" pos="0.05 0 0" quat="0 0.707108 0.707108 0" fovy="75"/>
<!-- to add gripper -->
<!-- Add sphere -->
<geom name="workspace_sphere" type="sphere" pos="0 0 0" size="0.2" rgba="0 1 0 0.3" contype="0" conaffinity="0"/>

However, the sphere is not visible in the simulation.
How can I properly render a sphere that follows the end-effector's motion in robosuite 1.4.0? Alternatively, is there a better way to visualize the end-effector's trajectory in robosuite?