Fail to enable auth method via API way

Vault
1

When I enable azure auth method via API way with root token, always got following error tip.
{“errors”:[“backend type must be specified as a string”]}

And, I try other auth methods the result is same, when I use CLI or Web UI, all the action is successful.

curl
–header “X-Vault-Token: …”
–request POST
–data ‘{“type”: “azure”}’
https://127.0.0.1:8200/v1/sys/auth/azure

{“errors”:[“backend type must be specified as a string”]}

2 
curl -i -H "X-Vault-Token: $(vault print token)" -d '{"type": "azure"}' "$VAULT_ADDR/v1/sys/auth/azure"

works fine for me.

I suspect you have made some formatting error in your command which is not visible in your post - which has been further mangled by the forum software, e.g. converting things to angled quote characters.