How to create call function with dll file

how to create call function & how to create dll file for this call function

store(DLLFunction) "myimx.dll:KeyEvent"
+ any(key) > call(DLLFunction)

but I want to know how to create dll for this appropriate call function.

While these DLLs still work, they work only on Windows. Developing them is outside the scope of support we can provide on the forum. You can find documentation at https://help.keyman.com/developer/13.0/guides/develop/imx/