src/Builders/RouteBuilder.php
public function withMiddleware(string $middlewareClassName, array $middlewareProperties = []): self
    {
        $this->middlewareBindings[] = new MiddlewareBinding($middlewareClassName, $middlewareProperties);

        return $this;
    }
public function withMiddleware(string $middlewareClassName, array $middlewareProperties = []): self
    {
        $this->middlewareBindings[] = new MiddlewareBinding($middlewareClassName, $middlewareProperties);

        return $this;
    }
Binds a single middleware class to the route

@param string $middlewareClassName The name of the middleware class to bind
@param array $middlewareProperties Any properties this method relies on
@return self For chaining