This content is design for UE4, you need the Modiverse plugin, for more info check the wiki : https://deepvoodoogames.com/kjmod_wiki/index.php/Main_Page
Deathrun is a mod for modiverse ispired by the mod of the same name from Gmod. Yout can fork this project and use it to build your own mod.
If you want to learn about making a map for Deathrun mod checkout the example map : https://github.com/Roxxas96/KJM-Deathrun-ExampleMap
Happy coding !