POST request from the app - https://android.jlelse.eu/handmade-backend-for-android-app-using-python-flask-framework-b173ba2bb3aa

somefile.kt

val jsonObj = JsonObject()
jsonObj.addProperty("title", "rhythm")
jsonObj.addProperty("singer", "meee")
jsonObj.addProperty("text", "Jack and jill went up the hill to fetch a pail of water!")

//  POST demo
APIKindaStuff
        .service
        .getVectors(jsonObj)
        .enqueue(object : Callback<ResponseBody> {
            override fun onFailure(call: Call<ResponseBody>, t: Throwable) {
                println("---TTTT :: POST Throwable EXCEPTION:: " + t.message)
            }

            override fun onResponse(call: Call<ResponseBody>, response: Response<ResponseBody>) {
                if (response.isSuccessful) {
                    val msg = response.body()?.string()
                    println("---TTTT :: POST msg from server :: " + msg)
                    Toast.makeText(applicationContext, msg, Toast.LENGTH_SHORT).show()
                }
            }
        })