RPG Maker MZ ships with autosave out of the box, but I feel it's a bit limited. Hence I've made the N_EnhanceAutosave plugin.
What it does
Lets you stop autosaves from increasing the "Save Count" variable (can be turned off).
Lets you disable autosaves for individual maps (for example Test maps).
Adds a window that displays whether an autosave is in progress, has succeeded, or has failed (can be turned off).
Adds a Plugin Command to trigger autosaves at any time during an event. Useful after a lengthy cutscene, a completed quest, or even shortly before an important decision.
In short: you're free to use it on any project (commercial or not) or modify it as you wish, as long as you won't remove the license and the copyright from the plugin.