This API is free and has no rate limit.
The lyrics are fetched from the @stef-0012/synclyrics NPM, which takes the
lyrics from Musixmatch, LrcLib.net and Netease.
Just make a HTTP GET request to the /lyrics endpoint with your song's metadata as query parameter.
artist - Song's artist.
author - Alias for artist.
track - Song's name.
song - Alias for track.
album - Song's album.
length - Song's length (in ms).
duration - Alias for length.
lyrics & source might be null if none of the providers
have the lyrics of your song.