Sr2RuO4 has been a focus of intense research since past 25 years for the possibility of correlated topological superconductivity. The key to superconducting order parameter lies with the momentum space structure of superconducting gap Δ?(?) on each band i. Because the energy scales are so low, it has never been possible to measure the Δ?(?) of Sr2RuO4. We have used millikelvin spectroscopic-imaging scanning tunneling microscopy (SI-STM) to study superconducting state of Sr2RuO4. At T=90mK, we visualize a set of Bogoliubov scattering interference wavevectors ??:?=1−5 consistent with gap nodes/minima, that are all closely aligned to the (±1,±1) crystal-lattice directions on both the α- and β-bands. Taking these observations in combination with other very recent advances in theory and experiments, the BQPI signature of Sr2RuO4 appears most consistent with Δ?(?) having ??2−?2 (?1? ) symmetry.