How to Encode H265 with Pixel Streaming

I need to use pixel streaming in UE5.2 to watch more than 5k resolution in web, I found that the encoding in the engine source code can only support up to 4096*4096 resolution, but the source code also wrote the code to use H265 encoding, but it doesn’t tell exactly how I should use it.
I would like to know how I can use pixel streaming to view more than 5k resolution, and if I need to use H265 for encoding, what do I need to do.