Request the list of "eligible" promo items that can be manually granted to the given
user. These are promo items of type "manual" that won't be granted automatically.
An example usage of this is an item that becomes available every week.
public static SteamAPICall_t RequestEligiblePromoItemDefinitionsIDs(CSteamID steamID) { InteropHelp.TestIfAvailableGameServer(); return (SteamAPICall_t)NativeMethods.ISteamGameServerInventory_RequestEligiblePromoItemDefinitionsIDs(steamID); }