Creating a Custom Referral Section for Email Design

Hey guys 🙂 I've just designed my own custom referral-section in a draft post (using these guides https://www.beehiiv.com/support/article/6915674583703 + https://www.youtube.com/watch?v=R7oBvEeOiko ) But I cannot find how to save this section as a universal design element to use in other mails?? You've got any tips? Thanks man!