I can’t sign in with my existing Apple ID the system shows the notification like verification failed could not communicate with the server

Hello! This seems to be a problem connecting to the server. Make sure you have strong Wi-Fi connection. If it still doesn't connect, wait for a bit. Last, you can connect Apple Support: Contact Apple for support and service - Apple Support

I can’t sign in with my existing Apple ID the system shows the notification like verification failed could not communicate with the server