In the 1st paragraph is a link to the previous article of the same experiment a few months ago, that has some more details mentioned:

researchers have managed to release 2.5 MJ of energy after using just 2.1 MJ to heat the fuel with lasers.

the positive energy gain reported ignores the 500MJ of energy that was put into the lasers themselves.

https://www.theguardian.com/environment/2022/dec/12/breakthrough-in-nuclear-fusion-could-mean-near-limitless-energy