認可リクエストにおける PKCE 利用の強制化

curl -v -X POST .../auth/authorization \
    -H "Authorization: Bearer <Service Access Token e.g., Xg6jVpJCvsaXvy2ks8R5WzjdMYlvQqOym3slDX0wNhQ>' \
    -H 'Content-Type: application/json' \
    -d '{"parameters": "redirect_uri=...&response_type=code&client_id=...&scope=..."}'

{
    "resultCode": "A124301",
    "resultMessage": "[A124301] The authorization request does not contain 'code_challenge' parameter. See RFC 7636 for details.",
    ...
}