You can find both the German and English versions of the FSE Consitution here.
The German version (pp. 2-13) of the Constitution, registered at Vereinsregister (association register) of the Amtsgericht Hamburg (Hamburg court), is legally binding. The English version (pp.14-24) is a translation produced by the FSE office.
Modifications were ratified by the 2019 General Meeting of Football Supporters Europe on 6th July 2019 and entered into force on 28th October 2019 (cf. article 15.1.).