Contact Form 7 – 5.0 on_sent_ok

I’ve read the 5.0 update and seen that on_sent_ok no longer works, however, I need to get the contact form to open up a wedding brochure upon completion. This is what is currently on my contact form

on_sent_ok: “location = /uploads/2018/02/Wrenbury-Hall-Wedding-Brochure-2018.pdf’;”

I don’t have any access to any php files to make these changes so need to know how to get around this, otherwise I cannot update the plugin as it stops supporting it.

The page I need help with: [log in to see the link]