Tried building this on local but it doesnt work

I have built it using the instructions but register shows 404 page and nothing works.

Proxy error: Could not proxy request /auth/login from localhost:3000 to https://whistleblower-backend-production.up.railway.app/api.
See https://nodejs.org/api/errors.html#errors_common_system_errors for more information (ECONNRESET).