The request body needs to be of type object, but we found invalid JSON

Hi,
I have this sample API definition below:
> /schedules/v1/Available:

    post:
      tags:
        - Available
      security:
        - ApiToken: []
      description: |
        Update available record
      requestBody:
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/Available'
          text/json:
            schema:
              $ref: '#/components/schemas/Available'
          application/xml:
            schema:
              $ref: '#/components/schemas/Available'
          text/xml:
            schema:
              $ref: '#/components/schemas/Available'
        required: true
    ...

and the following schemas:
> schemas:

Available:
  type: object
  properties:
    ID:
      type: string
      nullable: true
      description: ID of user
    department:
      type: string
      nullable: true
      description: Department Name
    date:
      type: string
      nullable: true
      description: Available Date
    isavailable:
      type: string
      nullable: true
      description: |
        Indicates whether available. Valid values are **Yes** and **No**

My content-type is application/xml and in my body, I pass an xml data. When I make a post, I get a schema validation error of β€œThe request body needs to be of type object, but we found invalid JSON”. Is XML as content-type not supported?

OAS3 does have support for XML. I guess internally Postman is only expecting JSON.