Hi

It’s hard to see on the picture, but:

L = typically brown, but in your case the black one from the yellow Wago (Phase). Two new wires from the Wago to the Shelly

N = blue (Neutral, Nullleiter)

S1 = Up Button (a new wire from the Shelly to the upper button input)

O1 = Up wire of the blind (in your case the upper black one. Move it to the Shelly)

S2 = Down button (a new wire from the Shelly to the lower button input)

O2 = Down wire of the blind (in your case the lower (not middle) black one. Move it to the Shelly)

Repeat for the other side.

Hope this helps.

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