Mapping diagnostic level command to Private-CLI API

[dull hemlock]

I tried to map below diag level command command

vserver services access-check authentication show-creds -node node-01 -vserver svm01 -win-name
WIN_USER

to respective private-cli REST API endpoint as
below.

https://CLUSTER/api/private/cli/vserver/services/access-check/authentication/show-creds?privilege_level=diagnostic&node=node-01&win-name=WIN_USER&return_records=true&return_timeout=60

When GET operation is performed aginst above URI, below is the response recieved.

{
"error": {
"message": "invalid operation",
"code": "3"
}
}

Can someone help map this command to correct
private-cli API endpoint?