Documentation: Missing OIDC client documentation on custom claims

[schicho]

Problem

The documentation with examples on the website is excellent, yet I cannot find any details how to retrieve custom claims.
I think this may just have been forgotten? Or one is supposed to know intuitively?

I followed the example for the Flask OIDC client and can get all the standard claims.

oauth.register(
    "organization",
    server_metadata_url="[...]",
    client_kwargs={"scope": "openid email profile"},
)

@bp.route("/auth")
def auth():
    token = oauth.organization.authorize_access_token()
    session["user"] = token["userinfo"]

However there is no documentation for custom claims, as shown below.

Proposed solution

Given a well known config with

"claims_supported": [
        "address",
        "birthdate",
        "client_id",
        "cn",
        "company",
        "department",
...
]

add example code to the documentation at on how to retrieve the custom claim for department for instance.

I have looked around the issues here, looked on Stack Overflow, nada.
I can make a contribution and extend the examples, when someone can help me with this.

[schicho]

I am aware of issues referencing custom claims, yet no examples with OIDC get me there.

The closest is #549, but that does not help me either