How to POST logical type decimal values for Avro records to Confluent Rest Proxy?

Question

We are using the Confluent Rest Proxy to communicate with Kafka and need to test a variety of data. We are using the Rest Proxy to allow a vendor to communicate with our Kafka system.

One of our fields in the Avro schema has a logical type of decimal. To keep this simple, let's assume the schema shown here:

{
  "fields": [
    {
      "name": "fieldName",
      "type": "string"
    },
    {
      "name": "amount",
      "type": {
        "logicalType": "decimal",
        "precision": 16,
        "scale": 2,
        "type": "bytes"
      }
    }
  ],
  "name": "Sample",
  "namespace": "com.test.sample",
  "type": "record"
}

It's easy enough to write to the topic via a Java producer, using Avro Tools to produce the appropriate class files. But when attempting to use the Rest Proxy, we have to pass values such as this:

{"value_schema_id":132,"records": [{"value":{"fieldName":"Field Name","amount":"\u0001ã"}}]}

This was copied from a record created via the Java producer and then downloaded from the topic. But in the amount field, we'd like to be able to pass a value such as 123.45. We're using Postman for the most part to send data. Is there a way to do this with a logical decimal field and without having to create and serialize the data first to see the representation such as \u0001ã?