I'll just quote from the rules:
"You may use pre-made, publicly available, and purchased assets, as well as GDevelop's built-in asset library, or other assets you have the legal rights to use. Just remember to credit properly. "
"You can use pre-existing code, extensions, functions. But do not write code specifically for this jam, ahead of time."
If it's publicly available and not copyrighted you should be fine.