You can sync prompt response to create/update Klaviyo subscriber.
Connect to Klaviyo
Go to prompt connections page and connect to your Klaviyo account. Klaviyo subscriber sync option will only be shown to accounts that are connected to Klaviyo.
Klaviyo Subscriber Sync
Edit prompt and select
Sync. Then locate
Klaviyo Subscriber and turn it on.
All other configurations and fields are optional.