Existing target has no 'swift compiler code generation' section

I found out by accident how to do it: create a new swift file and include all necessary targets (Xcode asks at the end of the file setup). Then Xcode asked me if I wanted the Bridging Header to be created and - much more important - added the Swift section to the target

For any new users the setting you are looking for is under "swift compiler - general"

Just scroll down from swift compiler - code generation. Also make sure you select "all" and not "basic" (at the top) basic hides some features.