1- Place this project on /home/$USER/Pictures.
2- Put environment variables in a file to pass to crontab:
env > ~/.cronenv && sed -i '/%s/d' ~/.cronenv
3- Set an entry in crontab table by crontab -e
:
*/15 * * * * env $(cat ~/.cronenv | xargs) python3.8 /path/to/project/bing-wallpapers.py