Hi
i have 2 custom post type (songs, artists) that by relation filed that connect with together, every songs post have a relation field that store artist that relate the song post
i getting data for mobile app by rest api
but i need filter api result post base acf filed like getting songs post that related to a artist post
rest api : http://www.example.com/wp-json/wp/v2/songs
i need something like : http://www.example.com/wp-json/wp/v2/songs?artist=1234
that return songs post that artist field is 1234
i found some tutorial but they are more than 2 years ego and they not work