How to post JSON Object direct using Retrofit in android Kotlin (Using MVVM Pattern)

Question

I am using retrofit for posting data to server as below

  @POST("web_php/app_user_login")
    suspend fun loginApi(@Body body: RequestBodies.LoginRequestBody): Response<LoginResponse>

 data class LoginRequestBody(
        val user_name: String,
        val user_password: String
    )

But I want to post JSON Object directly just like as below

 data class CreateAuditRequestBody(
        val auditJsonObject: JSONObject
    )

  @POST("web_php/create_first_audit")
    suspend fun createAuditApi(@Body body: RequestBodies.CreateAuditRequestBody): Response<CreateAuditResponse>

But It gives an error. Kindly Help me. Thanks