Unable to create test step under testcase using rest api provided by zephyr enterprise standalone

I am getting error:405 method not allowed.

I am trying to create test step using Zephyr Enterprise Standalone, PFB the url and the request for reference.

RestAPI URL: https://att11111.zephyrdemo.com/flex/services/rest/latest/testcase/1/teststep

Request:

{
"id": 1,
"tcId": 1,
"maxId": 1,
"steps": [
{

"id": 1,
"localId": 2,
"orderId": 2,
"step": "Go to test",
"data": "user name and password",
"result": "login to the system."
}
],
"testcaseVersionId": 1
}