Start QR Code Challenge

curl --request POST \
  --url https://api.authsignal.com/v1/client/challenge/qr-code \
  --header 'Content-Type: application/json' \
  --data '{
  "action": "<string>",
  "custom": {}
}'

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