https://gitlab.freedesktop.org/pipewire/pipewire/-/blob/6168067cb2a45ffa3c92aff1135659feaf9c1240/src/modules/module-echo-cancel.c#L95
Please fix libpipewire-echo-cancel to libpipewire-module-echo-cancel.
libpipewire-echo-cancel
libpipewire-module-echo-cancel