Wow, that "Figure 2. Breadboarding" picture is messed up - took me asking myself "the board looks reasonable, but why alligator clips and not special probes... Wait, where are the scope inputs? why is text so broken, compression artifacts?" before I got the idea to google the scope model and realized the whole picture is AI slop.

I think it's pretty safe to assume the rest of article is AI slop as well, and that if author did not notice the (numerous and obvious) problems with the picture, they missed lots of other problems in text as well. If you want to simulate some circuits, use some other post to learn.