The Flood reacts very poorly to no rainwater. Therefore it is rather not suitable from my point of view.
But you can use the contacts for example with something like this:
https://www.ebay.de/itm/Regensenso…872.m2749.l2649
connect them, then it should work very well
MIHO Could you please let me know how to wire it to Shelly flood? Shelly Flood has 3 pins ...