Traefik 2.1.2 toml command traefik error: field not found, node: etcd

Traefik Traefik v2
1

use traefik 2.1.2

run

./traefik --configFile=traefik.etcd.toml
show error
command traefik error: field not found, node: etcd

my traefik.etcd.toml is

[providers]
[providers.docker]
exposedByDefault = false

[providers.etcd]
endpoints = ["127.0.0.1:2379"]
rootKey = "traefik"
2

Hello,

etcd provider is not supported in v2.1

https://docs.traefik.io/v2.1/providers/overview/#supported-providers

This provider will be supported in the next version (v2.2)