3 wires together in a 3 way wago ,the brown live from new fitting ,the brown that is going to the 1st fitting and the blue ( which should have a brown sleeve)being the switched live .( The two marked L&N in your original pic)
All earth conductors sleeved yellow/ green and fitted into an insulated terminal block ,including any earth wire from the fitting.
The new fittings neutral connects to the other blue wires that are currently together in a wago.
And at the switch positions the blue wires should be sleeved brown to show they are live not neutrals.