How to create a dll in CodeBlocks?

Question

C++ / C#

Hello. Not a sishnik, java developer. But at work, I had to work with equipment (including Java). To the equipment there is a dll with which you need to work. I found instructions on how to work with dll from Java, but I got stuck, in fact, at the step of creating this very dll (test). The instruction uses CodeBlocks. The source code for sish files is given, but the step of creating a dll is not described. I looked online and didn't find clear instructions. It seems that he created the dll project, and installed MinGW, and naturally added the necessary files. But the build does not give anything. Tell me what to do, where to look.