how to get rid of blotchiness in a dark scene

I used Premiere to produce an .mp4 video, starting with an .mp4 video captured via AVerMedia ReCentral 4 from a website. In scenes that are very dark, there is blotchiness in the dark areas. How can I get rid of the blotchiness?

Details:

1. Premiere Pro v 25.x running on Windows11.
2. Source video: .mp4, codec avc1, 3840 x 2160 pixels, 60 fps, frame rate mode variable, color space YUV, 8 bit depth, progressive scan, 16:9 aspect ratio.
3. Output video: .mp4, codec avc1, 3840 x 2160 pixels, 60 fps, frame rate mode constant, color space YUV, 8 bit depth, progressive scan, 16:9 aspect ratio, format profile Main@L5.2.