I am facing a null pointer exception in findviewbyid function for kotlin(Android)

Logcat of Android studio states that "Caused by: java.lang.NullPointerException: findViewById(R.id.rvMaps) must not be null"

App installed on android emulator or physical device doesn't open up due to nullpointer
exception.

Been trying to find the solution from a few days but wasn't able to find on.

Help me out with this.
Thanks!

Code in MainActivity.kt is:

package eu.tutorials.mymaps
import androidx.appcompat.app.AppCompatActivity 
import android.os.Bundle
import androidx.recyclerview.widget.LinearLayoutManager
import androidx.recyclerview.widget.RecyclerView
import eu.tutorials.mymaps.models.Place
import eu.tutorials.mymaps.models.UserMap
class MainActivity : AppCompatActivity() {
private lateinit var rvMaps: RecyclerView
override fun onCreate(savedInstanceState: Bundle?) {
rvMaps = findViewById(R.id.rvMaps)
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val userMaps = generateSampleData()
// Set layout manager on the recycler view
rvMaps.layoutManager = LinearLayoutManager(this)
// Set adapter on the recycler view
rvMaps.adapter = MapsAdapter(this, userMaps)
}
private fun generateSampleData(): List<UserMap> {
return listOf(
UserMap(
"Memories from University",
listOf(
Place("Branner Hall", "Best dorm at Stanford", 37.426, -122.163),
Place("Gates CS building", "Many long nights in this basement", 37.430, -122.173),
Place("Pinkberry", "First date with my wife", 37.444, -122.170)
)
),
UserMap("January vacation planning!",
listOf(
Place("Tokyo", "Overnight layover", 35.67, 139.65),
Place("Ranchi", "Family visit + wedding!", 23.34, 85.31),
Place("Singapore", "Inspired by \"Crazy Rich Asians\"", 1.35, 103.82)
)),
UserMap("Singapore travel itinerary",
listOf(
Place("Gardens by the Bay", "Amazing urban nature park", 1.282, 103.864),
Place("Jurong Bird Park", "Family-friendly park with many varieties of birds", 1.319, 103.706),
Place("Sentosa", "Island resort with panoramic views", 1.249, 103.830),
Place("Botanic Gardens", "One of the world's greatest tropical gardens", 1.3138, 103.8159)
)
),
UserMap("My favorite places in the Midwest",
listOf(
Place("Chicago", "Urban center of the midwest, the \"Windy City\"", 41.878, -87.630),
Place("Rochester, Michigan", "The best of Detroit suburbia", 42.681, -83.134),
Place("Mackinaw City", "The entrance into the Upper Peninsula", 45.777, -84.727),
Place("Michigan State University", "Home to the Spartans", 42.701, -84.482),
Place("University of Michigan", "Home to the Wolverines", 42.278, -83.738)
)
),
UserMap("Restaurants to try",
listOf(
Place("Champ's Diner", "Retro diner in Brooklyn", 40.709, -73.941),
Place("Althea", "Chicago upscale dining with an amazing view", 41.895, -87.625),
Place("Shizen", "Elegant sushi in San Francisco", 37.768, -122.422),
Place("Citizen Eatery", "Bright cafe in Austin with a pink rabbit", 30.322, -97.739),
Place("Kati Thai", "Authentic Portland Thai food, served with love", 45.505, -122.635)
)
)
)
}
}

I dont know the exact reason of this issue but I tried to access the rvMaps recycler view
through its id in the MainActivity.kt which threw a nullpointerexception crashing the app.

rvMaps = findViewById(R.id.rvMaps)

>write this code below

setContentView(R.layout.activity_main)

code

override fun onCreate(savedInstanceState: Bundle?) {
//rvMaps = findViewById(R.id.rvMaps) //you can't write here
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
rvMaps = findViewById(R.id.rvMaps) //it should be below setcontentview
val userMaps = generateSampleData()
// Set layout manager on the recycler view
rvMaps.layoutManager = LinearLayoutManager(this)
// Set adapter on the recycler view
rvMaps.adapter = MapsAdapter(this, userMaps)
}