He resuelto instalando en un fresco laravel 8 con estos comandos laravel-websockets

borrar composer.lock

composer require "guzzlehttp/psr7:^1.7"
composer require "psr/log:1.1.4"
composer require beyondcode/laravel-websockets

Iniciar servidor de sockets
php artisan websockets:serve


Probando eventos con Tinker
php artisan Tinker

event(new App\Events\NewMessage("Nuevo Mensaje"))