The Federation of Astronomical Societies endorse The Dark Skies Matter initiative.

Their website is https://www.darkskiesmatter.org.uk/ and previewed below

Theme: Illdy. © Copyright 2019- 2024. All Rights Reserved. - Header image - Hubble image of Snow Angel, Sharpless Sh2-106. Credit: NASA, ESA, and the Hubble Heritage Team (STScI/AURA).
The FAS Secretary:- TBN, secretary at fedastro dot org dot uk.
or via contact page https://fedastro.org.uk/fas/contact-us/contact-secretary/