As Stefan already stated: The standard way would be to connect the output of the push button to the "SW"-Input of the Shelly and the "O"-Output of the Shelly to the impulse relay. Anyhow, even your suggestion would work, but you would not see at the Shelly App if someone switched on the Lamp via the push button.
The most professional way would be to substitute the impulse-relay by the Shelly. You don't need it anymore. All current functions can be realized via the Shelly itself.