curl --request POST \
  --url https://grantex-auth-dd4mtrt2gq-uc.a.run.app/v1/webauthn/assert/options \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "principalId": "<string>",
  "authRequestId": "<string>"
}
'

{
  "challengeId": "<string>",
  "challenge": "<string>",
  "allowCredentials": [
    {
      "id": "<string>",
      "type": "<string>"
    }
  ],
  "userVerification": "required",
  "timeout": 123
}