I have translated the phrase 書き込みによると which, and if I'm right, means "According to the writing". I want to know more about the structure and grammar rules used here. I found it in this article.
書き込みによると means "according to the entry/note."
書き込み = (handwritten) note; post; jotting; entry.
によると = a JLPT 1 grammar point that means "according to". You can read more on this grammatical form here.
Hope this helps!