How to Create a Form Redirect in Squarespace
What you’ll need: A standard form
How to set up a form redirect:
Select edit on the top left hand side of the site preview
Double click on the form on your page or add a new one
Select post submit (under edit form fields and above Google reCAPTCHA)
Toggle on the redirect option
Click the gear icon to open the link settings menu
Link to a page on your site, an existing page anywhere on the web, or upload a file
When you are all done, hover over the word done on the top left hand side of your site preview and click the save option
Important info: This is specific for form blocks inside Squarespace and can also work if you have lightbox mode enabled.