Issue related to curl for PUT command

Hello Team,
We are trying to do curl to use PUT request for creating role. But we are getting error as 404 not found.

url -XPUT “https://hostname:port/_opendistro/_security/api/rolesmapping/bai_dev_administrators” -H ‘Content-Type: application/json’ -d’
{
“backend_roles” : ,
“hosts” : [ “ip of LDAP” ],
“users” : [ “username” ]
}’ --insecure