The couple key paragraphs:

So the scientific team at Interlune, led by planetary scientist Elizabeth Frank, decided to get creative. Inside a vacuum chamber at the company’s offices, ionized helium was accelerated into lunar regolith. This process mimicked the solar wind, delivering equivalent helium-ion exposure at a far higher rate. Over the course of four hours, 15,000 years of solar wind was implanted into the lunar regolith.

The company’s scientists then heated this material and observed the decomposition of minerals through a process known as pyrolysis. The helium implanted into the lunar regolith was released at the same temperatures that scientists have observed helium-3 being released from rocks returned by Apollo astronauts. This gave confidence that the simulant accurately mimicked lunar conditions.

So we can get helium-3 out of regolith. Now we just need to go get it.