bool SendInvitation ( const [FUniqueNetId](API\Runtime\CoreOnline\Online\FUniqueNetId) & LocalUserId, const [FOnlinePartyId](API\Plugins\OnlineSubsystem\FOnlinePartyId) & PartyId, const [FPartyInvitationRecipient](API\Plugins\OnlineSubsystem\Interfaces\FPartyInvitationRecipient) & Recipient, const [FOnSendPartyInvitationComplete](API\Plugins\OnlineSubsystem\Interfaces\FOnSendPartyInvitationComplete) & Delegate )