I downloaded LiveSplit and the splits but the programme does not start the run or does any splits on its own, do I have to convert it into an auto splitter somehow?

Make sure you have to auto splitter enabled and configure properly livesplit is also very janky with auto splitters so try using new splits and setting it up again

You need to make sure your timer is based on "game time" rather than "real time" (or have one of each!). Go into "edit layout", double click on the timer (or add a new one with the big plus sign), change "timing method" to game time

And of course go into "edit splits" and activate the autosplitter if you haven't already

@Klagarn

Thanks man, that was super helpful, now everything works perfectly :)