Right under Organizer Options select Tickets / Registration.
Then on the left under Promote Event / Tracking.
Under Tracking in section Tickethop Callback (Webhook) activate the integration type - Server Call.
There in the URL you deposit: http://www.brandsmill.com/xingwebhook?m=<Client No.> & F = <Form No.> & E = <tag>
The important parameters are your client number and the form number of the "XING Event Ticket". In addition, the parameter tag allows the transfer of a keyword by e.g. to assign the ticket directly to an event.
As soon as a ticket is bought, the handovers from XING Events will start at brand's mill "the webhook". For the form "XING Event Ticket" a workflow will be started in brand's mill ... which you can customize.