Legally recognise non binary gender identities

I'm a young person in the UK and I don't understand why non-binary identities still aren't recognised in law. Non-binary people exist and deserve documents that match who they are. Other countries already allow an X gender marker or legally recognise non-binary people. Updating UK law would make things fairer, more accurate, and reduce confusion in education, work, healthcare and travel. We are asking for the basic recognition already afforded to us in many other countries, especially in Europe.