In kiosk mode, you need to select one application which will run always. In Headwind MDM, this app is called the "Content application" and is set up in "MDM settings".
The user cannot switch between applications in kiosk mode, because Home and Recents buttons are disabled.
However the content application can start other applications itself. Therefore, you may need to enable multiple applications in kiosk mode.
To enable an application, you need to know its package ID. Here is the instruction how to enable multiple applications: https://qa.h-mdm.com/1175/ In general, you enable (allow) multiple applications in kiosk mode in the same way as in non-kiosk (launcher) mode.
Notice: in Android 9 and above, you can adjust kiosk mode settings, for example, enable Home and Recents buttons.