Check out type76 on github to see what I am talking about.

Key points:

• It's free
• Produces ASCII animation that can be recorded as video, or played back interactively

Timing of sync needs to be set manually. This thing doesn't work with other voices.

Mozilla's built-in voice is ugly and barely usable, in fact, not useable.

I recommend... https://www.naturalreaders.com/online/ for voice generation

And you can record audio output with blackhole.

Conclusion

The type76 bot it an interesting way to create the lipsync animation. It's a good example, to be used in learning or writing your own.

The main point to address is the timing. This is a main topic in lipsync.