MainActivity.kt

//The URI of the photo that the user has picked
var photoUri: Uri? by remember { mutableStateOf(null) }

//The launcher we will use for the PickVisualMedia contract.
//When .launch()ed, this will display the photo picker.
val launcher = rememberLauncherForActivityResult(ActivityResultContracts.PickVisualMedia()) { uri ->
    //When the user has selected a photo, its URL is returned here
    photoUri = uri
}