Where are the merge fields to sync/automate magento discount codes with email automation journey?

[Saf98]

We have installed the plugin to send automated emails when a customer leaves a product in their basket. So this is an abandoned basket . However, I want to add the discount code to these emails but without manually copy/paste codes in the email templates. Why can't we have some merge field for automation?

Preconditions Adobe Commerce ver. 2.4.5-p7 Mailchimp v103.4.61

Steps to reproduce Not Applicable

Actual and Expected result Actual Result. - No option to merge fields

Expected Result - Should have merge fields for variables, for example, discount code, customers name, email, product details held from basket.

Actual Result - There is no feature

Additional information The documentation lacks a detailed explanation of how to set up custom fields.