A search for heavy scalar resonances decaying to a pair of Z bosons in the 4-lepton final state is presented, with the data collected by the CMS detector from 2016 to 2018 at center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 138 $\text{fb}^{-1}$. A model-independent approach is applied to model signal, background and interference processes. Large mass region is covered from 130 GeV to 3 TeV, and different width assumptions and production mechanisms are tested. No significant excess is observed, and upper limits on the production cross section of the resonance multiplied by its decay branching ratio of decaying into two Z bosons at 95% confidence level are computed.