You could replace the the latching relay by a Shelly and have the two momentary acting push buttons wired directly to SW input of the Shelly.
Depending on existing wiring/cabling the Shelly could be installed behind one of the momentary acting push buttons (if a Neutral wire would be available, or in the Switchboard (instead of the latching relay, by using on of the available DIN rail clips).
Such you could switch the light by use of one of the Push buttons or via Smartphone.
Shelly could be confirgured that Light would go off by pressing local Push Button, by Smartphone or after a fix configured Time by Shelly (Off delay).
Without having to pull new wires, easiest would be to swap the existing latching relay by a Shelly 1.
This wiring shows the situation if the latching relay would be replaced by a Shelly 1:
https://www.shelly-support.eu/index.php?attachment/11055-ar768-tasterschaltung-png/
Here a Link to a Shelly clip which holds the Shelly on a DIN rail:
If the local Push Buttons would be equipped with a Lamp, this supply would either have to come from local available Line (Lamp would always be on), or by use of a separate wire which would then have to come from O terminal of Shelly (Lamp of local Push Button would only be on if Light would be on).
In the APP the current state of light could be checked by looking at the small vertical Line of the on/off button (grey = light is off / light blue = light is on, if activated in the App).
Least effort might be to leave the Switchboard wiring as is and install the Shelly behind one of the existing Push buttons, if a Neutral is available behind one of the two Push buttons.
If you want to do it this way, it would most probably be of a problem with illumination of local Push Buttons, then you would either need to replace the local Push buttons by a compatible type, or simply remove the illumination.
Disadvantage of this solution (with Shelly ahead of Latching relay) would be that you wouldn't know what state the light has, when looking at the App.
Once we know what you want, we might be able to provide more specific advices.