I want to implement the automatic capture function that shows the game view in Unity - unity3d

Question

I'm using this as a capture.
ScreenCapture.CaptureScreenshot($"Screenshot{_shotIndex}.png", size);
But the CpatureScreenshot() is too slow.
So I tried different scripts but failed. One of them is that I succeeded in capturing the scene view.
public void TakeTransparentScreenshot(Camera cam, int width, int height, string savePath)
{
// Depending on your render pipeline, this may not work.
var bak_cam_targetTexture = cam.targetTexture;
var bak_cam_clearFlags = cam.clearFlags;
var bak_RenderTexture_active = RenderTexture.active;
var tex_transparent = new Texture2D(width, height, TextureFormat.ARGB32, false);
// Must use 24-bit depth buffer to be able to fill background.
var render_texture = RenderTexture.GetTemporary(width, height, 24, RenderTextureFormat.ARGB32);
var grab_area = new Rect(0, 0, width, height);
RenderTexture.active = render_texture;
cam.targetTexture = render_texture;
cam.clearFlags = CameraClearFlags.SolidColor;
// Simple: use a clear background
cam.backgroundColor = Color.clear;
cam.Render();
tex_transparent.ReadPixels(grab_area, 0, 0);
tex_transparent.Apply();
// Encode the resulting output texture to a byte array then write to the file
byte[] pngShot = ImageConversion.EncodeToPNG(tex_transparent);
File.WriteAllBytes(savePath, pngShot);
cam.clearFlags = bak_cam_clearFlags;
cam.targetTexture = bak_cam_targetTexture;
RenderTexture.active = bak_RenderTexture_active;
RenderTexture.ReleaseTemporary(render_texture);
Texture2D.Destroy(tex_transparent);
}
How do I capture a screenshot in Unity3d with a transparent background?
I need to capture the game view, but this script does the scene view.
Inevitably I tried to implement a feature that was automatically captured using CaptureScreenshot() and Coroutine. it was too slow to work.