Render Text over SpriteRenderers

Unity Engine
1

Hallo everyone,
I have kind of a situation where I want to render Textmeshpro text over a sprite render element to make a screenshot from it to be able to send it as an image.

My parent is a canvas elment becuase the whole level is just 2D.

Then for the combination of two sprite rendert a foto and an overlay I have an extra camera.

Now I want to add some text over the overlay. The text changes depending on the time.

Question is: How can I render the TextmeshPro now over the overlay.
Here is how I combine the two images.

            rt = new RenderTexture(1448, 2048, 24);
            fotoCam.targetTexture = rt;
            screenShot = new Texture2D(rt.width, rt.height, TextureFormat.RGB24, false);
            // Die Kamera rendern, einschließlich des Overlays
            fotoCam.Render();
            // Gelesene Textur aus der Kamera-Render-Textur
            RenderTexture.active = rt;

            texture = new Texture2D(rt.width, rt.height, TextureFormat.RGB24, false);
            texture.ReadPixels(new Rect(0, 0, rt.width, rt.height), 0, 0);
            texture.Apply();

            byte[] bytes = texture.EncodeToPNG();

            var fileWasWrittenSuccessfully = false;
            while (fileWasWrittenSuccessfully == false)
            {
                try
                {
                    using (FileStream fs = new FileStream(Path, FileMode.Create))
                    {
                        fs.Write(bytes, 0, bytes.Length);
                        fs.Close();
                    }
                    fileWasWrittenSuccessfully = true;



                }
                catch (IOException)
                {

                    fileWasWrittenSuccessfully = false;
                }
            }

Thanks in advance