Correct, you replace replace --rdzv_backend=etcd with --rdzv_backend=c10d. Command will look something like
python -m torch.distributed.run
    --nnodes=1:4
    --nproc_per_node=$NUM_TRAINERS
    --rdzv_id=$JOB_ID
    --rdzv_backend=c10d
    --rdzv_endpoint=$HOST_NODE_ADDR
    YOUR_TRAINING_SCRIPT.py (--arg1 ... train script args...)

docs: torch.distributed.run (Elastic Launch) — PyTorch master documentation 3