When Spotify updates its official app, these "mods" often break. You will likely need to re-run the installation scripts periodically to keep them working.
While these tools offer a "free" premium experience, they come with significant caveats: Security Concerns
If you truly can’t pay, use the official free tier or switch to a different free ad-supported service (e.g., SoundCloud, Pandora Free). The risk of losing your playlists and account to a ban is not worth skipping a 30-second ad.