Custom post type block doesn’t show custom post types

Hello!
I added a custom post type to my theme which is working as expected.
I tried to show the custom posts with the custom post type block. But, on the right hand side, at the block settings, the dropdown “Choose what to display” allows me only to select post or pages but not my custom post type. Is there anything I have to do to add my cpt to the dropdown?
Thanks in advance for your reply!