Im speedrunning Roblox speed run 4 , 5 levels

Youtube is a video hosting platform, not recording software. OBS is the defacto standard for recording and streaming.

I recommend using OBS Studio to record your runs.

If you mean accuracy, I think maybe something has been lost in translation. Do you mean for timing your runs?

I personally use Premiere Pro as it conforms to the hours:minutes:seconds:frames timecode however I'm sure there is free video editing software that also lets you time things by frames. I would maybe ask in the Roblox community though to see how others time things as sometimes there can be funny rules about how runs are timed.