I hate the phys.org summaries. They don't really seem to understand what they are talking about.

Preprint or whatever: https://arxiv.org/pdf/2208.05557.pdf

Edit:

They are observing https://en.wikipedia.org/wiki/Feshbach_resonance in NaLi gas that has been cooled down to 1.8µK.

In a nutshell when the applied magnetic field is almost precisely 334.92 Gauss the NaLi molecules couple together a lot more than normal because the magnetic field affects the energy levels of the molecules (the electrons in the molecules). When the energy levels match then certain coupled states are far more likely to happen.

Previously this has been observed between atoms but not between molecules (NaLi)