How do I set referral links for divi email optins?

[noname12]

I followed the tutorial:
https://www.elegantthemes.com/blog/...ibe-with-divis-software-marketing-layout-pack

to create a page with "Follow Us" and social media icons.

Now I want to change this around and create a referral page instead with a Share Button. And give incentive to my users that for every 10 people coming through their referral link will get first month-free. How do I go about doing that? Any help is appreciated. Thank you in advance.