This is the definition of gender ID adopted by the UN. It is extremely problematic. Let's see why.

1. All persons have some form of gender identity.

Not a good start. It imposes on people a gender ID without their consent. I do not have a gender ID. Does it mean I am not a person? Replace person with 'human being'. Does it mean I am not a human being? Very dangerous talk.

2. Gender identity refers to each person's deeply felt internal and individual experience of gender.

What is gender in this sentence? If it is gender ID, definition is hopelessly circular. If it is sex, then why not call it sex? It would be marginally more rational.

But again, I do not have an individual experience of being female. I just am female. Like I am human. We do not have a human ID. We just are. UN seems to have a problem with reality.

3. which may or may not correspond with the sex assigned
at birth.

The usual canard. Sex is not assigned at birth, it is recorded correctly on visual inspection alone in 99.98% of cases. In the remaining cases, more testing is necessary. All humans are male or female.

But at least now we know gender is not sex, but can correspond with sex. Or not. So how do we know when gender and sex do not match?

4. including the personal sense of the body and other
gender expressions, including dress, speech and mannerisms.

'Personal sense of the body.' So whether one has a female or male body I imagine. How do you reconcile this with the female penis/girl dick?

It seems a body is female if its male inhabitant says it is. Actual female bodies have to go through invasive surgery and damaging hormones to be accepted as male bodies. The male vagina is like 'Fetch' in Mean Girls. It's not going to happen.

'other gender expressions'.
What could this be? No clue. Name? Pronouns? How are these deeply felt? They are all, what's the word now, constructs. How can constructs be deeply felt, internal and individual? Surely this means nothing.

'including dress, speech and mannerisms'.

So gender stereotypes then. Your gender ID is how well you fit stereotypes of your sex. And we need to protect them in law, and arbitrarily assign a gender ID to all persons, even those who wish to have no such thing?

Now ask yourself, 'cui prodest'? Who benefits? Who benefits from replacing sex as a significant category with gender ID?
Who benefits from erasing the distinction between males and females, the only criterion used to determine who has women's rights?

Can women escape the constraints that gender imposes on their sex? No, because they cannot escape their sex.
Can men access the rights women have on the basis of their sex? Yes, if gender ID replaces sex.
BINGO