Great question — answering as the UphillTech team:
Specify your details through the affiliate field of the request. $request->affiliate = new Types\Affiliate(); $request->affiliate->customId = '...'; $request->affiliate->geoTargeting = true; $request->affiliate->networkId = 2; $request->affiliate->trackingId = '...';
Full answer by user2066189: https://stackoverflow.stackexchange.com/a/44618998 (CC BY-SA 4.0).
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