Declip music from the best source you have. Prefer an original WAV or FLAC over an MP3 made from the same recording, because lossy encoding alters the samples around damaged peaks. If only an MP3 is available, upload it to the music declipping tool and choose Better Declipper in Auto mode to analyze smeared clipping. Converting that MP3 to WAV before upload does not recover missing information. Preview the restored version and export a WAV to avoid another lossy encoding step.