Array
(
    [http_code] => 401
    [curl_error] => 
    [response] => HTTP/1.1 401 Unauthorized
Date: Mon, 11 May 2026 13:51:28 GMT
Content-Type: application/vnd.api+json
Content-Length: 229
Connection: keep-alive
pkh: 3d1b
x-klaviyo-req-id: a54c99ce-bc13-49d7-9e1c-31b9e73ab2e1
x-envoy-upstream-service-time: 8
Server: cloudflare
cf-cache-status: DYNAMIC
X-Content-Type-Options: nosniff
Strict-Transport-Security: max-age=31536000; includeSubDomains; preload
CF-RAY: 9fa1a89cfe28d81b-SJC

{"errors":[{"title":"Incorrect authentication credentials.","status":401,"detail":"Incorrect authentication credentials.","source":{"pointer":"/data/"},"id":"a54c99ce-bc13-49d7-9e1c-31b9e73ab2e1","code":"authentication_failed"}]}
    [request_url] => https://a.klaviyo.com/api/v2/lists
    [request_headers] => Array
        (
            [0] => Content-Type: application/json
            [1] => Authorization: Klaviyo-API-Key pk_9a6f04e24ec981ab4a9cde2016b2c571ce
        )

)