Measurements of Higgs boson properties in events where the Higgs boson decays into a pair of photons are presented. The measurements are based on a sample of proton-proton collisions at $\sqrt s$ = 13 TeV collected by the CMS detector at the LHC from 2016 to 2018, corresponding to an integrated luminosity of 137$fb^{−1}$. All major Higgs production modes (gluon usion, vector boson fusion, vector boson associated production, and production associated with top quarks) are considered in the analysis. Properties of the Higgs boson, including standard model signal strength modifiers, production cross sections, and its couplings to other particles, are found to be in agreement with the standard model expectations.