This is the wrong place to ask for this,
Add a hotkey for splitting in settings, set up splits and their respective times. I'd set an easy key for splitting that is easy to reach, but not easy enough to misclick.
I'd leave times empty for now until you hit your first run or pb, to see how much you improve or how bad rng you get.
Also you can play without splits, but splits help with seeing improvements.
I recommend setting up splits the way your route goes, for example, if you do ice then wind then lightning and last fire. Set them up Ice, Wind, Lightning, Fire
You can also add other splits like First box done, or second box done, whatever you feel suits you. I hope this helps.
Also on splits that have been premade, I didn't find any examples of someone sharing their splits, so create your own depending on route as I said earlier.