The USD assets will be automatically downloaded from the Omniverse server when training or running an agent.
As a backup, here you can find the following:
- anymal_c.usd: ANYmal-C legged robot asset downloaded from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.2/Isaac/IsaacLab/Robots/ANYbotics/ANYmal-C/anymal_c.usd
- cf2x.usd: Crazyflie quadcopter asset downloaded from http://omniverse-content-production.s3-us-west-2.amazonaws.com/Assets/Isaac/4.2/Isaac/Robots/Crazyflie/cf2x.usd
Disclaimer: I do not own these assets, I am providing them here for backup purposes only.