Fixed issue with merge_var not being able to accept array as value. Specifically, I wanted to put in 'groupings' , which takes an array of arrays in and subscribes the user to a particular group in a list (https://apidocs.mailchimp.com/api/2.0/lists/subscribe.php).
Fixed issue with merge_var not being able to accept array as value. Specifically, I wanted to put in 'groupings' , which takes an array of arrays in and subscribes the user to a particular group in a list (https://apidocs.mailchimp.com/api/2.0/lists/subscribe.php).