CallButtons provide another way to have a GUI for end users. Click Playout→CallButtons to open the CallButton window.
To add a new button click right on a free space and select the Add Button context menu. Each time the Add Button menu is clicked a new button occurs on the CallButton surface.
To assign a task to a button right click on the button and select the context menu Select Task. This opens a window with all available tasks. Select one and click Add. By default, the taskname is used as caption for the button. If you want another caption then the taskname you can click right on the button and select Change Caption