Getting 404 error with Production check

Hi,

I am trying to generate the Open API  3.0 with post method and it is giving the error as

[
    {
        "errorCode": "NOT_FOUND",
        "message": "The requested resource does not exist"
    }
]

I followed the same steps in sandbox and it was working fine. Do we need any specific setup with production instance?

Below is the URL I am running

https://XXXX.my.salesforce.com/services/data/v58.0/async/specifications/oas3

and resource is

{
   "resources" : [
      "/services/data/v58.0/sobjects/Contact"
   ]
}