How to merge 2 room databases into 1 in compose?

I have created 2 seperate room databases following best practices in kotlin. 1 database for age and 1 for gender, how can I merge these 2 databases and represent them into "1" database? The order from top to bottom does not matter. How can this be achieved this?

Age database: https://gyazo.com/0074f2e4f002de9a3ad07ec593a826d4

Gender database: https://gyazo.com/c8b800b8f2f4fc6b43a9de2ddfdb1e7d

Any advice is appreciated!

My age database:

@Database(entities = [Age::class], version = 1, exportSchema = false)
abstract class AgeDb : RoomDatabase() {

    abstract fun AgeDao() : AgeDao

    companion object {

        @Volatile
        private var INSTANCE : AgeDb? = null

        fun getDatabase(context: Context) : AgeDb {

            val tempInstance = INSTANCE
            if (tempInstance != null) {

                return tempInstance
            }

            synchronized(this) {

                val instance = Room.databaseBuilder(
                    context.applicationContext,
                    AgeDb::class.java,
                    "dropdown_age"
                ).build()
                INSTANCE = instance
                return instance
            }

        }
    }
}