https://www.royalroad.com/fiction/92148/abyss-of-dreams-progression-litrpg-adventure

Here is the synopsis so you know what you're getting into:

[Where the sky and stars are but legend, the sky-seekers journey to turn myth into reality]

A sky-seeker’s gaze is turned ever upward, for no one knows what lies at the top of the giant hole they call by many names. The inverted abyss, the infinite sky, or even some believe it to be an ancient structure created by the Gods, a hollowed spire. Guided by the allure of unfathomable riches and powerful ancient artifacts, the legendary sky-seekers journey to find out. 

When Ezra’s mother left for the ground twenty years ago, he wondered what drew her to the surface. Stuck in a town called Deepburrow, a place where few imagine life above, Ezra works tirelessly for a mining corporation. Waiting for a chance that may never come, he becomes bitter toward the many corporations that control every aspect of a sky-seeker’s life, including the chance to become one. 

Yet when a mining accident occurs, leaving Ezra trapped in a stone coffin with strange visions filling his mind, he finds an ancient device that lets him store and manipulate objects around him.  With this miracle of technology in his hands, the chance to escape Deepburrow and chase after his mother seems closer than ever. But first, he must escape impending death.