Remotely switch a Sonoff MINI R4 Extreme

I’m wondering how to best go about this. I have a LED strip underneath my kitchen cabinets. Goes from 230v mains to the MINI R4 to a LED driver to a LED strip. I can turn it off and on in Home Assistant. So far so good. Now I would like to make an existing original light switch (currently not connected to anything) to trigger the MINI R4. How would I go about doing this? Install an MINI R4 in the actual physical wall switch and have that trigger the MINI R4 underneath my cabinet through Home Assistant? Seems weird. I don’t want to replace the existing light switches, but fine adding something in the back of it. I feel like I am missing something obvious…