In order for your module to be used within WinGate it needs to export a set of mandatory functions. The Using the WinGate Module Wizard creates these for you if you use it to create your solution/project.
For GUI modules
See InitialiseGUI
For Engine modules
See Initialise
For all modules
ModuleGetAPIVersion should return the version of the API that your module was compiled with. WinGate will check that the version returned from ModuleGetAPIVersion is the same as its own internal version. If they differ, the module will not be loaded.
Typically the function looks like so: