The project demonstrates a proper configuration of an API application uses TypeORM (over a PostgreSQL database) with Express.js and written in TypeScript. For the sake of the example it has a User entity with a UserRepository and migration alongside a UserSubscriber.
A configuration file needs to be created as a prerequisites which contains your database access information like the host, database name, username, etc.
Read the official TypeORM documentation to learn how to use entities, migrations, repositories and other tools properly.
The example uses a PostgreSQL database engine but you can change that in the ormconfig.json following the supported database drivers.
npm install
npm start