When your supporter completes a Registration form, they are taken to a Confirmation page. This page thanks them and can provide action items. It is fully customizable with the settings below.
To start, go to a Registration activity, and then select Confirmation Page from the left sidebar.
The design of the page is divided into two parts, the Content Section and the Actions Section. The Content Section contains the items in the top half of the form and is your acknowledgment that the supporter has completed the registration successfully.
The Actions Section gives them something to do, such as go to another page, follow you on various social media channels, and/or sign up to receive emails or texts from you.
Content Section
The Confirmation screen is where you can immediately thank your supporters for their contributions. The Content section gives you that initial touchpoint and confirms their answers from the registration form have been received.
Title
By default, it will say "Thanks, [first_name]!" in a cursive font. Like with all of the items on the Confirmation Page, you can hide this element with the Show/Hide switch.
The content can be anything you like, so if you wish to be more formal and say "Thank You" vs. "Thanks" or something more generic like "Thank you for taking our survey!" just edit the line. You can also change the color and style (Bold / Italic / Underline) of the font. 
It allows for variables, so the standard collected information on the form will be available in the Variables list. It will not have additional/custom variables you may have added to your form.
Subtitle
The Subtitle refers to the automated confirmation message about completing the form.
If you are using a non-payment registration form (not asking for donations) it will say "Thanks for your support! Your information has been saved."
If you are using a payment version of the Registration form it will show that the credit card has been billed. This will automatically show the last four digits of the credit card and the amount.
There is nothing editable on the Subtitle other than to Show or Hide the wording.
Thank You Image
You can show your supporters that you thank them for their support with an image. If you prefer not to use an image, you can use the Show/Hide switch to disable it.
If you would like to use your own graphic, click Update to upload the image and then Save it.
Message
The Message element is a standard Text message, which means you can format it with the rich text editor to make the wording bold, italic, change the font size, type color, etc. You may want to reword this to better represent the registration form.
You can also click Personalize to add extra information to your content from the standard fields in your forms.
At this time, additional form element items are not available in personalized messages on the Confirmation page.
Actions Section
The Confirmation page thanks your supporters for registering and can provide them with action items too. The Action section gives you four different options for them to complete.
Primary Action Button
After your supporters complete their registration, you may want to send them to your organization's web page or an Event Page. The Primary Action button allows this functionality by providing a personalized button and the link to the new website.
If you use a Primary Action Button without a Secondary Action Button, the button will expand to the width of the confirmation page. If you use both, they will be side by side.
Secondary Action Button
Do you want to give your supporters a choice of action? Then add a Secondary Action Button. The Primary Action Button will fill the button with the Activity's main color, and the Secondary Action Button will use the color to outline a white button with the color. 
If you use a Secondary Action Button without a Primary Action Button, the button will expand to the width of the confirmation page. If you use both, they will be side by side.
Follow on Social Media
Provide ways for supporters to follow you on Social Media with the Follow On Social Media options. You have the choice to show links to Facebook, Instagram, Twitter, and YouTube channels.
You can enter the address manually in this section or add them in the Main Menu > Settings > Shared Settings > Social Media section so they populate in all your Confirmation pages.
If you don't have a presence on one or more of these Social Media channels, you can click Edit content and turn off any you do not use.
Mailing List Subscription
Depending on how a supporter reached the form, you may or may not have collected their mobile number or email address, and if you leave those as optional entries on the form (not generally recommended), you may not have those contact points available. By enabling the Mailing List Subscription feature, you can not only ensure to collect either your supporter's mobile number or email, but you will have them explicitly opt-in to receive messages from you.