Or you could install PulseEffects Legacy to have PulseEffects work with PulseAudio.
PulseEffect now works with PipeWire instead of PulseAudio, so if you want latest PulseEffects you need to switch audio system to PipeWire, or you can stay on previous PulseEffect by using PulseEffects Legacy instead.
The solution I posted worked for me for a couple of days, then no more audio output. Pulseeffects loaded properly but was getting no output. Volume controls were set ok. I did not spend much time troubleshooting (shame on me), but instead uninstalled pulseeffects and anything pipewire related, reinstalled pulseaudio and all optional dependencies, and then installed pulseeffects-legacy.