Cabling/connecting question

I would like to use a Shelly 2.5 to automate our roller blinds and I would appreciate some help.

Our home is in a new building (in Germany) and besides the roller blind up/down switch we also have a blank plug box with access to the wiring at the top near the actual roller blind motor, so this is where I'd like to add the Shelly 2.5.

Behind the switch I see (see picture below) the switch has 4 cables connected, 3 brown ones (1 brown is Down, 2 others are L) and a black one (Up).

Up the top, the cables I see (see picture below) are the usual yellow/green (ground), blue (neutral) and brown (up? the grey from the connection scheme) as well as a black (down as per the connection scheme?) which all go toward the roller blind motor. In the wall there's also another, "unused" brown cable?

I assume the "un-used" brown at the top goes in the L's of the Shelly 2.5, right?

Right, I managed to connect the Shelly at the top but I somehow messed up the initial setup. The wifi appeared but somehow I did not add the device. The Shelly's red light seems to be blinking now? How do reset the device and attempt adding the new device again?

p.s. Is there a way to figure out which Wifi network my other Shelly's use? I have 2 networks and I forgot which one was for the smart devices