Array
(
    [http_code] => 401
    [curl_error] => 
    [response] => HTTP/1.1 401 Unauthorized
Date: Fri, 16 Oct 2026 02:25:02 GMT
Content-Type: application/vnd.api+json
Content-Length: 229
Connection: keep-alive
CF-Ray: a4b39c530994227e-SJC
CF-Cache-Status: DYNAMIC
Server: cloudflare
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
X-Content-Type-Options: nosniff
pkh: 3d1b
x-envoy-upstream-service-time: 17
x-klaviyo-req-id: 781d2ed5-e45b-4d36-84ae-830ac47b46e6

{"errors":[{"title":"Incorrect authentication credentials.","status":401,"id":"781d2ed5-e45b-4d36-84ae-830ac47b46e6","source":{"pointer":"/data/"},"code":"authentication_failed","detail":"Incorrect authentication credentials."}]}
    [request_url] => https://a.klaviyo.com/api/v2/lists
    [request_headers] => Array
        (
            [0] => Content-Type: application/json
            [1] => Authorization: Klaviyo-API-Key pk_9a6f04e24ec981ab4a9cde2016b2c571ce
        )

)