Magnetism is believed to play an important role in many quantum phenomena such as superconductivity and nematicity in iron-based superconductors. One of the signatures is that the dynamic spin-spin correlation length will always have response to these phase transitions. Recently, a new hedgehog spin-vortex crystal (SVC) order was discovered in CaK(Fe1-xNix)4As4. It would be interesting to study the spin-spin correlation length crossing the superconducting and magnetic transition temperatures in such a unique spin-vortex C4 phase compound without a static nematic order even nematic fluctuations. Thus, we propose to study of the dynamic spin correlation length of low energy spin excitations in CaK(Fe0.96Ni0.04)4As4 (Tc = 20.5 K, TN = 46.5 K) with centimeter-size single crystals by inelastic neutron scattering using high flux chopper spectrometer MAPS or MERLIN.