Blynk is great for many things… but as an IoT process, it is relient on the networking/internet infrastructure and the Server connection… Thus not so great for mision/life critical scenarios in which that very infrastructure can be easily disrupted.
Good old fashioned buttons, levers, switches, key pads and hard wiring are still necessary. As well as “Works without Blynk Server connection” code to link with those manual controls.
There is… but how well it can work automatically is a whole 'nother issue. Search this forum for other discussions about that.