Hi. Note that this is a forum for open-source software, which Aseprite is not:
Aseprite is a proprietary, source-available image editor […] Aseprite can be downloaded as freeware, (albeit it does not have the ability to save sprites) or purchased
(Aseprite - Wikipedia)
Aseprite is open source (under restrictions of their license) and can be compiled for free for personal use.
And this compiled version can save everything