Begin adding a passkey to the signed-in account

{
  "ticket": "tk_5c0a1d9e7b3f",
  "options": {
    "challenge": "Zm9vYmFyYmF6",
    "rp": {
      "name": "Acme",
      "id": "example.com"
    },
    "user": {
      "id": "01M5Y1G7AF0N78A9EP71BV68MT",
      "name": "ada@example.com",
      "displayName": "Ada Lovelace"
    },
    "pubKeyCredParams": [
      {
        "type": "public-key",
        "alg": -7
      }
    ],
    "timeout": 60000
  }
}