Humorously, they don't give a temperature, but they do mention "high-temperature superconducting" 14 times.

High temperature superconductors don't have to work at room temperature. As it doesn't require liquid nitrogen cooling, it's a lot easier to maintain and run.

If they're hitting 25T on a bore larger than a few cm then they're using supercritical 8K helium to cool REBCO superconductors OR they have a super secret new superconducting material that the rest of the world doesn't know about and hasn't been used in other practical application (exceedingly unlikely, drunk uncle conspiracy theory tier).