Local server

What config should be set in the server so that it can be accessed through both ddns and the local network? It would be desirable that gauges exchanged with blynk in a local network and all control through out.

If I understand your question correctly, it is not a server setting…

Setup a DDNS account and create such an address pointing to your router’s Public IP

Setup your router with port forwarding from the Public side to your Local Server’s private IP.

Then you just use your DDNS address in your App login