Facebook Conversion API warns me that PageView event missing event_id, but PageView event does not accept any parameters in the facebook develop document.
Even though I have uploaded event_id in all Conversions APIs, I still get a warning of missing event id.
You have to send an event id along with your pixel and conversion api. They have to be the same string for both, this way Meta can deduplicate your events avoiding double counting and messing up your metrics.
Check out https://www.facebook.com/business/help/823677331451951?id=1205376682832142