fix: import load_env_vars in app.py for environment variable management

Author: giuseppe99barchetta

api_service/app.py

@@ -12,6 +12,7 @@
 
 from api_service.utils.utils import AppUtils
 from api_service.config.logger_manager import LoggerManager
+from api_service.config.config import load_env_vars
 
 from api_service.auth.middleware import enforce_authentication
 from api_service.auth.limiter import limiter