I’ve been working in my role in network security for over a decade and I still feel like I don’t know anything sometimes. The thing I did learn though, was to recognize when I needed to improve my skills and when it was just imposter syndrome.
In your case, I would do it the way you are asked, rather than the textbook way. Then after things are sorted out, speak with them to figure out why they do it that way instead(be careful with your tone so you sound inquisitive rather than critical). If they’re worth working with, they will give you an answer beyond “because I said so”.