  We demonstrate the resonant excitation of two quantum dots in a photonic
integrated circuit for on-chip single-photon generation in multiple spatial
modes. The two quantum dots are electrically tuned to the same emission
wavelength using a pair of isolated $p$-$i$-$n$ junctions and excited by a
resonant pump laser via dual-mode waveguides. We demonstrate two-photon quantum
interference visibility of $(79\pm2)\%$ under continuous-wave excitation of
narrow-linewidth quantum dots. Our work solves an outstanding challenge in
quantum photonics by realizing the key enabling functionality of how to
scale-up deterministic single-photon sources.
