Purchase events are sent with "firebase_conversion" parameter set to 1 #32
Description
I'm trying to narrow down an issue with event attribution.
I'm collecting most of the GA4 data on the front-end of my website, however Add to cart, Remove from cart and Purchase events are being sent through Measurement Protocol. In order for these events to be properly attributed to the ongoing GA4 session and user actions, I'm taking the session_id from ga cookie and I'm sending it along with the timestamps with the forementioned events.
According to Simo Ahava, this should work: https://www.simoahava.com/analytics/session-attribution-with-ga4-measurement-protocol/
And it does seem to work fine with "add to cart" and "remove from cart" events. When I created a view in GA4 that shows me, for example, all kinds of statistics about acquisition from organic sources, the add to cart events show up assigned to specific sources.
However, none of the organic sources show any purchases. As a matter of fact, all the purchase events are being attributed to "Direct" source, without exception. None of them have been attributed to anything else.
That led me to investigate the events in GA4 and I've noticed that all the "purchase" events sent from this library are marked with the parameter "firebase_conversion" set to "1". This parameter is not set at all for Add to cart and Remove from cart events.
When I googled, I found few unanswered questions about firebase conversions always being attributed to "Direct".
Could this be the culprit? Since firebase conversions are dedicated for in-app purchases, it's possible that Google is overriding these conversions as "Direct". Is there a reason for the "Purchase" event to be sent with this parameter? Is it possible to disable it?