(1) Sync your git repo before working
  git pull

(2) Commit your change after working to ensure the git repo has the latest tex file.
  git commit -a
  git push

(3) Build pdf
  make

(4) Modify tex files in Google Doc (Let me know if you cannot open the following directory)
  https://drive.google.com/drive/folders/1fJREW7-tIUT0BXGg-iwVE2p42uAKj_Y_