After installed, just press “ctrl + alt + S” and you will save a new duplicate file.

Settings

Changing the shortcut:

You can change the hotkey any time you want, you just have to go to Preferences > Keymap > and search for “Save as Duplicate File”, and you can change the shortcut!

Add Separator Before Numbers

In the addon preferences, you will be able to select between adding a separator before numbers or not:

With Separator: BlendFile_3.blend

Without Separator: BlendFile3.blend