According to your description you were unable to use the Simulation 3D Pedestrian block.
It is now available in the Simulink library since the 2022b release.
You can add it to your Simulink workspace and add a Simulink 3D scene configuration block to check it's functionality.
You can set it's properties just like other Simulatiobn 3D blocks with attributes like X, Y, Yaw.
For more information you can check it's documentation here: Implement pedestrian in 3D environment - Simulink (mathworks.com)
