Tutorial: this tutorial will show you how to build underground. You'll also see how to merge items to create a transport method to get underground.

You can receive the Symptomatic from Daily Ops, after reaching level 50, or you can purchase it with gold bullion from Minerva in game.

If you would like to purchase the little blue generator, or the catwalks that i use in this video:

go to help.bethesda.net
click on the fallout 76 icon
choose the following answers:
Billing / Purchase / Code
PS/XBOX/or PC
I need help with the Atomic Shop
Yes
I want to purchase an Atomic Shop item for myself
enter your fallout ID
from the item list drop down box choose
Future-Tec Bundle
(generator)
Shelter Catwalk Bundle
(catwalks)

You will receive an email informing you how many atoms the item(s) you want to purchase will cost, you MUST REPLY that you agree to having those atoms removed from your account.

If there's anything specific you would like me to do a tutorial about, please say so in comments!

Happy building!