There are 2 different types of Sandbox accounts:
Developer Sandbox Account: this is for people who want to test integrations. Developers usually use this. It can be requested by submitting a form. Learn more about the functionalities here: Developer Sandbox Accounts.
- Agency Sandbox account (best known as Reseller Sandbox Account): this is a professional account to easily showcase ActiveCampaign to clients and leads. An Agency partner can use it to build integrations, pipelines, automations, and then show it to potential buyers. By using the Account Snapshot Tool, the Agency Sandbox account can be copied to create new accounts for clients.