Simply use the below javascript to the OnSave event of the entity and check the “Pass execution context as first parameter” box in the Handler Properties to disable the auto-save property of the entity form.

function DisableAutoSave(context) {
var saveEvent = context.getEventArgs();
if (saveEvent.getSaveMode() == 70) { //Form AutoSave Event
saveEvent.preventDefault(); //Stops the Save Event

}

Happy Coding :)