Response Server duration in Laravel Middleware

Question

I am Trying to get the response Server Duration in my Middelware and save it in Sql DataBase , Here is my middelware

public function handle(LaravelRequest $request, Closure $next)
    {
       
        $this->startTime = microtime(true);

       return $next($request); 
    }

class AfterMiddleware  {
     
    public function handle(LaravelRequest $request, Closure $next)
    {
        
        $response = $next($request);
        
        $request->fingerprint();
        $RequestSaving = new Request();
        $endpoint=Endpoint::where("url",$request->url())->firstOrCreate(["url"=>$request->url()]);
        $RequestSaving->endpoint()->associate($endpoint);
        $RequestSaving->method = $request->getMethod();
        $RequestSaving->status = $response->Status();
        $RequestSaving->user_id = Auth::id();
        $RequestSaving->duration=microtime(true)-$this->startTime;
        $RequestSaving->result =$response->Content();
        $RequestSaving->save();   

        return $response;
    }

}

Everything works Fine only the part if the duration response that looks a littel bit complicated to me , Any ideas ?