URLConnection Error codes handling


I am using URLConnection to retrieve data from our API and I wanted to know how to retrieves network error codes from different platforms.

On the documentation URLConnection — Xojo documentation, the error differs depending on the platform (macOS, Windows, Linux).

I know I have to use #If targetMacos and #If targetWindows but I do not know how to import the constants of each platform.

Documentation links to some constants (i.e.: NSURLError for MacOS) .

Is there a declare to retrieve this list of constants for each platform ?

Thank you