Ha! It works. Thanks a lot. For foobar2000 users who want to change it themselves, go to C:\Users\<user name>\AppData\Roaming\foobar2000\user-components\foo_jscript_panel\samples\complete\js and open listenbrainz.js in a plain text editor, search for api and replace https://api.listenbrainz.org/1/submit-listen with https://beta-api.listenbrainz.org/1/submit-listen, then (re)start foobar.