How to set command while test in sim #10

After training like "python awd/run.py --task DucklingCommand --num_envs <...> --cfg_env awd/data/cfg//duckling_command.yaml --cfg_train awd/data/cfg//train/amp_duckling_task.yaml --motion_file awd/data/motions//" to train holonomous walk and get the checkpoint,how to test whether the duck can follow certain command or not.I use “python awd/run.py --test --task DucklingCommand --num_envs <...> --cfg_env awd/data/cfg//duckling_command.yaml --cfg_train awd/data/cfg//train/amp_duckling_task.yaml --motion_file awd/data/motions// --checkpoint <path_to_checkpoint.pth>” to test .Though it's gait is good ,I failed to find any interface to give it any of my commands to find if it can follow them.So how can I do so?Or what should I do if just want it walk along a straight line in Isaac Gym