To ensure that a buyer campaign is available in the lead flow, you need to publish it in PX through the Source Management feature.
Each lead in PX is related to a source, specifying the originating publisher and vertical. Through Source Management, you can enable campaigns for receiving leads as well as block or prioritize particular lead sources. There are a couple of different approaches for configuring lead traffic depending on the needs of a particular campaign.
For example, the buyer campaign should receive all leads except a certain publisher. You will then need to enable the campaign for the leads traffic and block corresponding lead sources. For full details on how to do this, click here.
Another common situation is when a buyer campaign should receive leads only from particular publishers in selected verticals. In this case, you can publish campaigns with a cherry-pick status, meaning that the buyer campaign will only receive leads from sources that you prioritize. Click here for more details.