Generate Passkey Authentication Options

curl --request POST \
  --url https://api.authsignal.com/v1/client/user-authenticators/passkey/authentication-options \
  --header 'Content-Type: application/json' \
  --data '{
  "challengeId": "<string>",
  "username": "<string>"
}'

{
  "challengeId": "<string>",
  "options": {}
}