volley | Android Volley , extended function | File Upload library

I'm using Volley library to communicate with my API. I'm pretty new to Android and Kotlin and I'm really confused about extracting keys from the following JSON data

I got a problem with my Volley POST in kotlin :

When I use this following code, my application go on "Response.Listener", but the array is null, so when I try to display the information I've just send, I can only get "null".

May you guys help me? :)

There is the kotlin code :

I'm new to android development and I'm trying to create a notification which pops up according to sensor data but before doing this I wanted to get a notification when I open the app(just to check whether the notification I created is working as I expected or not). I've tried running the code but I'm not getting any notification

Here's the main Activity

The following works with the REST api, however I am now trying to achieve the same in Android Kotlin

I've been trying to learn about Volley and hence I made a simple app which has a connect button and when the button is pressed it displays the response as a TOAST but when I press the button I cannot neither of the TOAST messages(response TOAST and error TOAST)

Here's the kotlin code:

I'm working on an Android app and currently stuck to link my database to my app for registration using volley but I get the problem: this is response:

com.android.volley.NoConnectionError:java.io.IOEXCEPTION: Cleartext HTTP traffic to 10.0.2.2 not permitted

Here is my MainActivity code:

I am making an attendance app on android studio, but whenever I try to log in using correct credentials I need to click twice on the login button to move forward to the next activity. I tried Asynctasks because of its background thread, after the same result I just reverted back

So, at first click nothing happens but as soon as please wait dialog box disappears and if I click like in under a second or two then it moves to the next activity.

clicking on login fetches some data from the server after the server has validated that the login exists and is correct. when data is received then the new activity is supposed to start since that received data will be shown in the next activity. (i have a list that is checked if it has data then it moves forward)

Login Activity code:

I am setting value of Team object in the parseJSON() method after getting information form my API. Even though the variable team has been declared static and initialized and I am using the this operator while setting data, data is not set in team object and when I do a team.getTeamName() I get java.lang.NullPointerException: println needs a message

Code:

I am populating my ArrayList after receiving data from my API and filling it in objects stored by the ArrayList but when I log the size of the ArrayList it shows up to be empty.

Here is my code :