First of all you require 3d builder if you want a text or a custom one whitout use of blender i recommend using font meme if you want cool fonts of movies or series once you have your text you copy the image to 3d builder
Once you have your 3d text, you need to save it the next step is to import it as obj
You can also use this (ThreeDText 2 - Roblox) but your tutorial is good since it has more fonts than the plugin.
some tutorial like this already exists
}didnt know it already existed