See discussion here:
https://www.mail-archive.com/search?l=mid&q=CAAGOGw8xabSxFadY31vT2ZLo%3DmN3o2XD2%3DkcdxKQgY8rgN_nZA%40mail.gmail.com
https://wiki.lyx.org/LyX/NewInLyX23
You can download LyX 2.3.0rc2 from ftp://ftp.lyx.org/pub/lyx/devel/.
-In case the primary ftp server is down or too slow you can try one of
-our mirrors listed at https://www.lyx.org/Download#toc11.
+In case the primary ftp server (based in France) is down or too slow you
+can try one of our mirrors listed at https://www.lyx.org/Download#toc11.
We appreciate your help in testing this pre-release!