lineNegotiateAPIVersion

[DllImport("coredll.dll", SetLastError = true)]
public static extern int lineNegotiateAPIVersion(
   IntPtr hLineApp,
   int dwDeviceID,
   int dwAPILowVersion,
   int dwAPIHighVersion,
   out int lpdwAPIVersion,
   ref LINEEXTENSIONID lpExtensionID
);

Microsoft documentation: Link