Work with Render Target in separate thread

Hi All! I have some question.
I write a class, which inherit from FRunnable.
So I implement some task execution in a separate thread in it.
Specifically, I would to read from the Render Target resource to the buffer in a separate thread.
So I call ReadPixels for Render target, but I have error and UE4 crash.
I clarify that the Render Target pointer I received as RenderTarget = CameraCapture->TextureTarget->GameThread_GetRenderTargetResource();
I even try to call ReadPixels through AsyncTask, but I have error from compiler. So I don’t know what mean ] () in this construction:

  • AsyncTask(ENamedThreads::GameThread, ](){
    RenderTarget->ReadPixels(RawPixels);
    });*
    How i can call ReadPixels for Render target resource in separate thread?
    Please help!

It seems to me that I found the answer to my question here Help with adapting RenderTarget->ReadPixels() to a multithreaded framework - Programming & Scripting - Epic Developer Community Forums.
Thank you all for your help