The Dawn of the Apocalypse Starts from the Cave Base That Can Be Upgraded

Save the wasteland with an ever-upgradable cave shelter. I'm just a migrant worker, I'm just too tired and just want to travel to relax, but I'm asked to save the world. This is too weird... Hey! That's not right. The technology in this world is more advanced than that on Earth. If we bring these technologies back to Earth, wouldn't we be able to make a fortune? ! Hahaha, okay, this salted fish like me finally has a chance to turn around, but... This opportunity is too desperate...