This function is for parsing Error Response from Json by using custom class for deserialization for specific error response by using custom class for deserialization JSON. Replace ErrorResponse::class.java with your own custom class. One thing to note is JSON can only be used once, so if you want to reuse it then store the JSON on a variable.

Function for Parsing Error Resposne from JSON

private fun parseHttpError(t: HttpException): String {
        val body = t.response()?.errorBody()
        val gson = Gson()
        val adapter: TypeAdapter<ErrorResponse> = gson.getAdapter(ErrorResponse::class.java)
        return try {
            val error = adapter.fromJson(body?.string())
            "Error ${error.status}: ${error.message}"
        } catch (e: Exception) {
            "Response failed to parse"
        }
 }