Using First Name from a form in the post-submit redirect "Thank You" page

Hello, We have a form on a page requesting First Name, Last Name, and Email. Once the user fills out the form, there is a post-submit redirect to a thank you page hosted by Squarespace. We use Zapier to send the info to Mailchimp from the form, however, I'm curious if there's a way to use the First Name from the form on the Thank You page via a tag or some other command to personalize the Thank You page.

novo.org/hearing-god-ebook

novo.org/hearing-god-ebook-confirmation

Oooh, I'm trying to do this too. Would love to hear the answer to this. 

@Murdoch Do you know how to set up the Confirmation page to go to mailchimp instead of squarespace? 
I followed this video (https://www.youtube.com/watch?v=siH1M1jZfzs), but my Confirmation and Thank You pages are coming from Squarespace instead of mailchimp. 

Hi @RTT-Falcon, I haven't gotten an answer on how to populate the FNAME on the subsequent Thank You page. Still hoping for some help.

We redirect them to a Thank You page hosted on Squarespace, however, we use Zapier (you can connect Zapier in the settings of a form on Squarespace) to place the contact in a group on Mailchimp and then a journey starts to automatically send them a Thank You email and then connect them into other emails we want to send them based on whatever their sign up is.