Request Body is Required

I am attempting to use the reindex API to combine indices for the month into one single index:

POST _reindex?pretty
{
  "conflicts": "proceed",
  "source": {
    "index": "my-index-2021.04.*"
  },
  "dest": {
    "index": "my-index-2021.04",
    "op_type": "create"
  }
}

...however, I am running into the following error in Dev Tools:

{
  "error" : {
    "root_cause" : [
      {
        "type" : "parse_exception",
        "reason" : "request body is required"
      }
    ],
    "type" : "parse_exception",
    "reason" : "request body is required"
  },
  "status" : 400
}

I did see an almost identical post about this, but no solution was provided.

Thank you!
Tim

That looks like a correct request to me. Can you check for any errant spaces or tabs in your request? I assume you're using Dev Tools.