使用MailChimp过滤器和操作成功提交表单结束后立即显示链接

Using Wordpress, I am currently trying to add a link - for downloading a document - that appears only when a form has correctly been submitted without error and right after the end of this form. I am using MailChimp as a plugin for the form.

The link would be very simple:

<a href="URL_DOCUMENT" target="_blank">click here</a>

I have found a filter which displays elements after the form fields :

add_filter( 'mc4wp_form_after_fields', 'filter_mc4wp_form_after_fields', 10, 2 );  

And an action which fires right after a form is submitted without any errors (success):

add_action( 'mc4wp_form_success', 'action_mc4wp_form_success', 10, 1 );  

Here are my limits understanding how are actions and filters working. I have tried each one of them seperatly, they work well. But with the action, my link appears at the very beggining of my page (right after the opening body balise). And with the filter, my link is always displayed.

I do not know how to combine thoses two effects. Do I still have to use these action and filter? How ? Or do I have to find another solution ?