How to parse JSON in Kotlin: a detailed guide for beginners

Hello everyone! I just started learning Kotlin and am trying to figure out JSON parsing. My task is to get data from an API and display it in an application. I know that in Java, libraries like Gson or Jackson are often used for this, but in Kotlin, as I understand, there are some peculiarities. \n\nThe problem is that I can't find a clear example in Russian. Everywhere they write about kotlinx.serialization, but I don't understand how to properly set it up and use it. I tried using Gson, like in Java, but ran into a null-safety issue — Kotlin complains about possible null values.\n\nHere's an example of the JSON I'm trying to parse:\n```json\n{\n "userId": 1,\n "id": 1,\n "title": "Title",\n "body": "Post text"\n}\n```\n\nI created a data class:\n```kotlin\ndata class Post(val userId: Int, val id: