MTL - Worlds’ Apocalypse Online - Chapter 8 accident

Year 2056, in a city in the Yuan Jiang Su Jin area. On top of a ruined, shattered six story residential apartment sits a teenager wearing a combat vest, militaristic trousers, and alloyed battle boots. On his back is a hexagonal shield and equipped is a blood-shadow battle knife. He sits there silently on the edge of the roof. At this time, the sparkling sky was shining and there was a refreshing breath within the air that blew towards him. However, there was only silence within the ruined, deserted city, with an occasional howl that makes your heart skip a beat.

Coming from the modern era, she was sent to a strange world. The body she possessed previously belonged to a young woman whose family was thrown away by their clan. However with the “Dan Fu Zong”, the inheritance from her old world, she steps on the path of cultivation, hoping to one day become an immortal.

- Description from Novelupdates

In a modern world where cultivators need a place to cultivate or vent their boredom, there are private businesses that set up instance dungeons with the aid of technology and cultivation magic to enable cultivators to train and commoners to experience the life of cultivation. They are called dungeon suppliers.
Xie Jin's one and only dream was to be a dungeon supplier and when his only relative passed away, the relative's inheritance gave him a plot of land and surprisingly, a 'System' Module which the relative had previously used.
With the help of the system, Xie Jin decided to pursue his dream of becoming the number one dungeon supplier.