The basic settings of Ditty Posts Ticker only allows you to choose a single post type. You can override this setting to create a ticker that displays multiple post types by activating the Advanced options and adding custom Query arguments (the selected post type will not matter if you override it using Query args).

1. Activate the Advanced options
2. Add the following to a row of Query args:
   1. Parameter: post_type
   2. Value (add post types separated by commas): post_type_1, post_type2, post_type_3
   3. Create array (you must create an array out of the Value): Select Split list
3. Save your ticker