4. The line from my /emacs file:

(require 'org-ref)
(require 'ox-bibtex-chinese)
(require 'reftex)

(setq org-latex-pdf-process
      '("pdflatex -interaction nonstopmode %f"
        "biber %b"
        "pdflatex -interaction nonstopmode %f"
        "pdflatex -interaction nonstopmode %f"))

I do not have ox-bibtex from melpa, this is what I have!

5. The exported .pdf file: