Electrician with Liander zegelrecht needed in Hilversum

In our home in Hilversum, a 3-phase connection (3×25A) and 3-phase meter are already installed. We have contacted Liander and they have confirmed that our 3×25A connection is active and approved. However, in the meter cabinet, the sealed (verzegelde) section belonging to Liander needs to be opened so that the 3 phases can be connected to the existing connection block/main connection. We are therefore looking for an electrician/electrotechnical installer with zegelrecht (zegelbevoegde) who can open Liander's sealed section, make the required connection, and then reseal it. Is there a specialist who can help us with this? Thank you!