Hey @-skxlinez-
You can add your local library to your playlists! 🙂
I suggest reading this article for more information on how it's done and what formats are supported.
Hope this helps, have a nice day!
SebastySpotify Star
Help others find this answer and click "Accept as Solution".
If you appreciate my answer, maybe give me a Like.
Note: I'm not a Spotify employee.