This plug in allow you to add or subscribe users to Klaviyo’s list with gravity forms.
Klaviyo offical website: https://www.klaviyo.com/
To achieve this, the pluin using Klaviyo list’s API (you can read more here: https://developers.klaviyo.com/en/reference/api_overview)
To use this plugin, you will need an API key provide by Klaviyo when using their services. That mean when using this pluign you are agree with Klaviyo’s Legal, Terms, & Policies here: https://www.klaviyo.com/legal