在Wordpress插件中使用PHP重定向页面

I'm trying to hack onto this wordpress plugin, to get it to redirect to another URL after a form is submitted, without any luck.

Basically, it's looking for a page with the ID of 'quiz' and inserting the contents from the plugin. Once the form is submitted, it refreshes the page and tries to insert new content (which I've removed). I want to have it redirect to another page all together after the folio3_process_form function runs.

Here's the paste of the plugin code: https://pastebin.com/xbkVQm3N

I'm guessing I need to use something like:

header("Location: http://example.com/myOtherPage.php");

I've tried that though, without any luck. Can't seem to figure out where it needs to go. Any help is much appreciated!