this has been suggested MANY times before. Now, when you write a snap topic, It says "this topic is similar to..." but why didn't you bother clicking on the topics that were the EXACT SAME THING???
https://forum.snap.berkeley.edu/t/autosaving-projects/
https://forum.snap.berkeley.edu/t/autosave-in-snap/
https://forum.snap.berkeley.edu/t/can-a-project-save-itself/
https://forum.snap.berkeley.edu/t/please-add-automatic-saving/