Install and connect the wires on your smart light switch to the wires inside your wall.
Install FUTINA smart home switch and socket, take the front plate off first, and connect the in wire to the in wire, the out wire to the out wire, the ground wire to the ground wire, and the neutral wire to the neutral wire. Secure your connections with wire connectors, and make sure you don't have any loose or exposed wire in the box. and make sure that all is right, then fix the device on the wall box, and screw the screws on the frame to the wall box, and put the front cover on the devices.