Use custom hosted control in Unified Service Desk
You can develop custom Unified Service Desk hosted controls if you have a special requirement that isn’t addressed by the predefined hosted control types. Dynamics 365 for Customer Engagement apps provides a Visual Studio template for creating a custom Unified Service Desk hosted control. The template provides basic code as comments to help you get started quickly with creating a custom hosted control.
Like the predefined hosted controls, custom Unified Service Desk hosted controls are also derived from the DynamicsBaseHostedControl class.