You can connect Promolayer to Klaviyo by adding your Klaviyo Public and Private API keys to the Promolayer dashboard.
Steps
Go to the Klaviyo API keys settings page here.
Copy your Public API key into the Promolayer dashboard.
Click Create Private API key.
Click the eye icon next to the newly created key to reveal it. Copy the whole key into the Promolayer dashboard.
Note: If you cannot access the API keys page or the API key area is missing from settings, you may not be an account administrator. Contact the administrator of your Klaviyo account and ask them to provide both the public and private keys.
Users Not Being Added to the List
If users are not being added to your list, your list may be set to double opt-in, meaning users must confirm their subscription via email before being added.
With double opt-in, users receive a confirmation email and are only added to the list after they click to confirm.
If you do not need email confirmation, go to your list's Settings and switch to single opt-in.