Convert Database Entity from Java to Kotlin

I am currently converting my projects to Kotlin and I have an app with Room database using Java.

My Entity in Java

@Entity(tableName = "store")
@Fts4
public class Store {

    @PrimaryKey
    @ColumnInfo(name = "rowid")
    private Long identification;

    @NonNull
    @ColumnInfo(name = "name")
    private String name;

    @ColumnInfo(name = "location")
    private String location;

    @ColumnInfo(name = "days_open")
    private int daysOpen;

    public Store(Long identification, @NonNull String name, String location, int daysOpen) {
        this.identification = identification;
        this.name = name;
        this.location = location;
        this.daysOpen = daysOpen
    }

    public Long getIdentification() {
        return identification;
    }

    @NonNull
    public String getName() {
        return name;
    }

    public String getLocation() {
        return location;
    }

    public int getDaysOpen() {
        return daysOpen;
    }
}

I convert it this way to Kotlin

@Entity(tableName = "store")
@Fts4
data class Store(

    @PrimaryKey @ColumnInfo(name = "rowid") 
    val identification: Long?,

    @ColumnInfo(name = "name")
    val name: String,

    @ColumnInfo(name = "location")
    val location: String?

    @ColumnInfo(name = "days_open")
    val daysOpen: Int?
)

Now I am having this error

java.lang.IllegalStateException: Room cannot verify the data integrity. Looks like you've changed schema but forgot to update the version number. You can simply fix this by increasing the version number.
 

Do we really need to do migration in this? Or I am wrong converting things. I am using Room 2.3.0.

implementation "androidx.room:room-ktx:2.3.0"
kapt "androidx.room:room-compiler:2.3.0"

When I updated the database version, this is the error

java.lang.IllegalStateException: A migration from 1 to 2 was required but not found. Please provide the necessary Migration path via RoomDatabase.Builder.addMigration(Migration ...) or allow for destructive migrations via one of the RoomDatabase.Builder.fallbackToDestructiveMigration* methods.
   

I added this code to my database

val MIGRATION_1_2 = object : Migration(1, 2) {
    override fun migrate(database: SupportSQLiteDatabase) {
        database.execSQL("
        // put changes here
        ")}
}

I don't know what to put inside of migrate function. Any idea?