Hello thongnguyenminh,
first of all thank you for the fast reply and also for including the debug feature in your plugin.
I’ve deactivated the functions.php lines and tried both options, with members and subscriber. I can tell that with the members option the response line in the debug contained some information [ID, email], while the response line with the subscribe option remained an empty array.
I will send you the detailed logs in private, since I’m not sure regarding personal information.
Does this indicate that your plugin works as it should, but this is a problem in the Klaviyo settings?
Any further help would be appreciated!
KR,
gunzi11