curl --request POST \
  --url https://api.zapperapi.com/{instanceId}/contacts/check-numbers \
  --header 'Content-Type: application/json' \
  --header 'X-Api-Key: <api-key>' \
  --data '
{
  "numbers": [
    "<string>"
  ]
}
'

{
  "numbers": [
    {
      "jid": "<string>",
      "exists": "<unknown>",
      "lid": "<unknown>"
    }
  ]
}