[SOLVED] LazyVerticalGrid : type mismatch

I'm following this tutorial : https://developer.android.com/codelabs/basic-android-kotlin-compose-practice-grid?continue=https%3A%2F%2Fdeveloper.android.com%2Fcourses%2Fpathways%2Fandroid-basics-compose-unit-3-pathway-2%3Fhl%3Den%23codelab-https%3A%2F%2Fdeveloper.android.com%2Fcodelabs%2Fbasic-android-kotlin-compose-practice-grid&hl=en#0

I use the LazyVerticalGrid object to display cards. My code is not working. The "it" (in { it ->) is seen as an Integer. It should be seen as a "Topic". I do not understand what I'm doing wrong.

package com.example.buildagrid

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.enableEdgeToEdge
import androidx.compose.foundation.Image
import androidx.compose.foundation.border
import androidx.compose.foundation.layout.Column
import androidx.compose.foundation.layout.Row
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.foundation.layout.padding
import androidx.compose.foundation.layout.size
import androidx.compose.foundation.lazy.grid.GridCells
import androidx.compose.foundation.lazy.grid.LazyVerticalGrid
import androidx.compose.material3.Card
import androidx.compose.material3.Icon
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Scaffold
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Alignment
import androidx.compose.ui.Modifier
import androidx.compose.ui.graphics.Color
import androidx.compose.ui.res.painterResource
import androidx.compose.ui.res.stringResource
import androidx.compose.ui.tooling.preview.Preview
import androidx.compose.ui.unit.dp
import com.example.buildagrid.data.DataSource
import com.example.buildagrid.data.DataSource.topics
import com.example.buildagrid.model.Topic
import com.example.buildagrid.ui.theme.BuildAGridTheme

@Composable
fun TopicGrid(modifier: Modifier = Modifier) {
    LazyVerticalGrid(
        columns = GridCells.Fixed(3)
    ) {
        items(topics) { it ->
            TopicCard(it)
        }

    }
}

@Composable
fun TopicCard(topic: Topic, modifier: Modifier = Modifier) {
    Card(
        modifier = modifier
        //.height(68.dp)
    ) {
        Row {
            Column {
                Image(
                    painter = painterResource(topic.imageRes),
                    contentDescription = "",
                    modifier = Modifier
                        .size(68.dp)
                )
            }
            Column {
                Row {
                    Text(
                        text = stringResource(topic.name),
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier
                            .padding(top = 16.dp, start = 16.dp, end = 16.dp, bottom = 8.dp)
                    )
                }
                Row(
                    verticalAlignment = Alignment.CenterVertically,
                    modifier = Modifier
                        .border(1.dp, Color.Blue)
                ) {
                    Icon(
                        painter = painterResource(R.drawable.ic_grain),
                        contentDescription = "",
                        modifier = Modifier
                            .padding(start = 16.dp, end = 8.dp)
                    )
                    Text(
                        text = topic.availableCourses.toString(),
                        style = MaterialTheme.typography.labelMedium
                    )
                }
            }
        }
    }
}

The "it" (in { it ->) is seen as an Integer. It should be seen as a "topic".

object DataSource {
    val topics = listOf(
        Topic(R.string.architecture, 58, R.drawable.architecture),
        Topic(R.string.crafts, 121, R.drawable.crafts),
        Topic(R.string.business, 78, R.drawable.business),
        Topic(R.string.culinary, 118, R.drawable.culinary),
        Topic(R.string.design, 423, R.drawable.design),
        Topic(R.string.fashion, 92, R.drawable.fashion),
        Topic(R.string.film, 165, R.drawable.film),
        Topic(R.string.gaming, 164, R.drawable.gaming),
        Topic(R.string.drawing, 326, R.drawable.drawing),
        Topic(R.string.lifestyle, 305, R.drawable.lifestyle),
        Topic(R.string.music, 212, R.drawable.music),
        Topic(R.string.painting, 172, R.drawable.painting),
        Topic(R.string.photography, 321, R.drawable.photography),
        Topic(R.string.tech, 118, R.drawable.tech)
    )
}

data class Topic(
    @StringRes val name: Int,
    val availableCourses: Int,
    @DrawableRes val imageRes: Int
)