New Shelly 1 owner question UK lights

I have a very straight forward lighting on an outhouse/summerhouse. Power from consumer unit with brown power, earth and blue neutral. It then runs to a standard one way switch then to a series of LED outside lights. I thought I could just take the power into the switch through the Shelly 1 and then into the series of outside lights ( with blue neutrals to a connector block) but unsure of wiring into and out of standard light switch. Hope I am overthinking this and some one can enlighten me. Thanks Malcolm

Tried that and the lights work independent of Shelly but can’t find/add the Shelly device on the Shelly app!!??…

When I hit add devices, it thinks about it for a few seconds then comes back to this screen..

Tried adding it onto another network in isolation and not adding it….I still be doing something wrong!!