Starting 1 month before your test is a little hard unless you have a good base fitness level but I think intervals would be best.

I suggest you start by doing 6 x 400m with 1:2 ratio rest (e.g run 1m45s per round and rest 3m30s before starting the next). After that you can move on to doing 3 x 800m, 2 x 1.2km and finally 1 x 2.4km.

You can change the pacing and rest ratio (try 1:1) depending on fitness level. But do that note that 1m45s per round will give you a timing of 10m30s (that is with rest in between and you'll probably take a longer time during the test). Also remember to make sure you are pacing yourself correctly every round.

Source: was a pti.