curl: (67) Authentication failure

[plawansai]

I wrote the docker-sftp.yml like this:
version: '3.2'
services:
sftp:
container_name: sftp-cv
image: atmoz/sftp:alpine
volumes:
- ./sftp-backup/cv/:/home/cv-sftp/cv
ports:
- "2222:22"
restart: on-failure
command: cv-sftp:P@ssword:::cv

However, when try to test with curl, the authentication failed, how should I do?
[root@k1]# curl -k -u cv-sftp:P@ssword sftp://localhost:2222/cv
curl: (67) Authentication failure

Thank you very much.