If you are downloading "dirzon books" that are comics or illustrated PDFs, you cannot just drag them onto a Kindle. You must use KCC to convert the PDF to MOBI or AZW3. Look for "Portable" PDFs because they convert faster and generate smaller Kindle files.
Since Dirzon is a file host, you typically don't browse their homepage (it often shows your own files). Instead, you use Google or Bing to search within the domain. dirzon books pdf portable
Google Search Operator:
site:dirzon.com "keyword" filetype:pdf If you are downloading "dirzon books" that are
For portable versions specifically:
site:dirzon.com "python" "portable pdf"
site:dirzon.com "medical" "compressed pdf" dirzon books pdf portable
You might want to contribute to the Dirzon community. If you have a large textbook or a rare novel, "dirzonizing" it (making it portable) is a valuable skill.