Add routing to <symfony-root>/config/routes.yaml:
kemoc_storehouse_api:
resource: ../vendor/kemoc/storehouse-api/Controller/REST
prefix: /storehouse/api/rest
type: rest
name_prefix: storehouse_api_rest_
...
Set <symfony-root>/config/packages/fos_rest.yaml
by: <this-bundle>/Resources/doc/fos_rest.yaml
If you do not have database then create it. Configure connection to DB.
Exec (after composer install):
php bin/console doctrine:schema:update --force