Three minutes is a common length for school and workplace typing tests, and long enough to test your stamina.
Over three minutes, small habits add up. A pause before every long word or a habit of fixing each mistake straight away costs a few seconds each time, and the results page adds them up for you: how much of the test went to fixing mistakes, to slow word starts and to long pauses.
Type at a pace you can hold. Starting fast and slowing down usually scores lower than an even pace from the first word to the last.
Start with accuracy. Below about 95%, mistakes are costing you more than slow fingers are, and the quickest gain is to slow down a little and type cleanly. Above that, look at the slowest letter pairs and the slowest finger: they point to the exact movements worth practising. The word review shows every word you typed, coloured by how long it took, so you can see whether long words or particular letters hold you up.
Take the same test again after a short drill. Three minutes is long enough that one lucky or unlucky word barely moves the score, so the difference between two runs is a fair measure.
About 40 WPM is enough for most office work; 60 WPM and above is fast. Accuracy above 95% matters as much as speed.
Fixing a mistake costs time, not points: words count once they are right.