We report helium absorption from the escaping atmosphere of TOI 560.01 (HD 73583b), a $R=2.8 R_\oplus$, $P=6.4$ d mini Neptune orbiting young ($\sim$600 Myr) K dwarf. Using Keck/NIRSPEC, we detect signal with an average depth $0.68 \pm 0.08$% in line core. The repeats during partial transit obtained month later, but is marginally stronger and bluer, perhaps reflecting changes stellar wind envir...