In order to support generation of UI forms, the logical types of the parameters that are used to generate the form fields should be mapped to a corresponding UI control. There could be different mappings for different scenarios, e.g. when the field may allow multiple values or a single value, so that the most appropriate control can be used, such as a ListBox vs. a DropDownList.
Normally if you extend your logical type from another base type in the model, it will automatically inherit the mapping to the UI controls from its parent. If your type does not extend any other logical type, or you just want to override the mapping to the UI controls, then the following tutorials outline this process for different UI technologies.