.sqlite file in AppName.app is not there

I am preparing for a custom migration of my app. I am following the tutorial BookMigration: HERE.

When I show contents of my AppName.app file I don't see any Model1.sqlite file so I can't find my old model to do the migration. When I open the tutorials BookMigration.app file, there is a Model1.sqlite file. However, in both projects I can see .mom files for the entity models.

Do you have a clue what I have to do in order for the .sqlite file to appear? Any help welcomed