How this app can help
WHMCS is a web hosting automation platform.
The WHMCS add-on allows ActiveCampaign Resellers the ability to import all of their ActiveCampaign plans and create product names, descriptions, and their desired markup or discount, all on a default custom domain or a client-set custom domain. In addition, you can create Package Upgrades between all ActiveCampaign Reseller products.
Check out the listing in the official WHMCS Marketplace for full details.