On a case-by-case basis, PostPilot can support legacy API key connections with Klaviyo.
Unless advised by our account management team, connecting to Klaviyo using our native app is easier, faster, and more secure!
For more information, please visit our help center article.
Note: this capability must be enabled for you by your account team before it can be used in our app.
Step 1
First head to the Integrations page. Scroll down to Klaviyo and click Manage:
Then, click the "connect via API key" link shown below the main connection button: 
Note: If the manage button is not available, please use this direct link to add your connection: https://app.postpilot.com/klaviyo_connections/new and proceed to Step 2.
Step 2
You will then need to input your Klaviyo API credentials and select the Shopify store connected to your Klaviyo account. You will need a private API key.
Follow the steps outlined in Klaviyo's documentation to create a new private key.
When creating the key, it's important to ensure the key grants sufficient permission to PostPilot in order to function!
If your API key isn't configured correctly, it will not work.
When creating a key, you must ensure this key provides read-only access to List, Profiles, and Segments, as seen here:
Step 3
Once you have input your Klaviyo API Key in the appropriate field click the Save button.
(If needed, you can reference Klaviyo's documentation to locate a previously-created key!)
Congrats, the integration is now enabled! 🚀