Command not recognized when starting example repository

[RabbitSW]

I am trying to start the example repository from "sdk/packages/example", but the "yarn start" command results in this error:
$ SKIP_PREFLIGHT_CHECK=true react-scripts build "SKIP_PREFLIGHT_CHECK" no se reconoce como un comando interno o externo, programa o archivo por lotes ejecutable. error Command failed with exit code 1.

I already tried to reinstall the "react-scripts" but the error still appears.