"Thank you reply" with visitors name from contact form/booking form

Hello,

I have a booking form on https://www.zorbas.dk/booking/
When users a filling this in they will be redirected to another page as i want to use it for analytics. The redirection page is: https://www.zorbas.dk/tak-for-din-mail-booking/

In the answer on this page i would like it to be Hej *name of user.
How can I do that?
I want it to take the name from the contact form and use it in the start to make it more peronal.

I know it is possible to add a php function to autosend email with users name. But in this case I am interested to give the answer on the page: https://www.zorbas.dk/tak-for-din-mail-booking/