Festival text-to-speech

Im trying to play in a web that make the sound of your moves (lichess.org).
I try festival and im having this error problem:

festival --server
server    Sat Apr 22 18:49:57 2023 : Festival server started on port 1314
client(1) Sat Apr 22 18:50:35 2023 : accepted from localhost
SIOD: unknown voice cmu_us_awb_cg
SIOD: unknown voice cmu_us_awb_cg
SIOD: unknown voice cmu_us_rms_cg
SIOD: unknown voice cmu_us_rms_cg
SIOD: unknown voice cmu_us_slt_cg
SIOD: unknown voice cmu_us_slt_cg

And, there is no sound.

You will have to do what is explained on Using_the_festival-us_voices

This applies for Firefox, not sure about other browsers …