Here is a quick explanation on how to use the somewes to time your runs:

first go to https://somewes.com/frame-count/

Then upload your run, just drag and drop it into the given panel or paste the youtube URL in the box below.

Once your video shows find the first frame that is needed (here in every category it is when the cursor appears after the door cutscene) and press "set start frame".

After that find the end frame (most of the time it will be when both players step on the area before the end door) and press "set end frame".

Now your time shows on the right side under "Results". So you can copy the time under "Video Time" and paste it into your run information and send your run to be verified.

That should be all if there are still questions left fell free to ask!