Using renergy.lu means you use the public pages as information. Figures on public simulators are estimates, not an offer and not a bill.
An energy-community contract, a membership, and an invoice exist only after they are agreed with the community. They are not formed by browsing this site.
Do not try to identify a member from what the public pages show. Those pages are deliberately coarse.
Luxembourg law applies. The courts of Luxembourg have jurisdiction, without limiting a consumer's mandatory rights.