To test `migrations-config.js` restart your keyserver terminal. Ensure `DB version: 31` log line is visible.
To test `setup-db.js` create new database and update `secrets` folder so that it points to new database instance. Start your keyserver.
In both cases using a database connection tool of choice (I prefer to use `mariadb` terminal command), ensure `olm_notifications_sessions` table is present and its structure matches SQL statement used to create it.