Possible error in documentation regarding deduplication

[mj3052]

In the documentation it is stated that you should add a parameter called x-fb-event_id to the GA4 event on the web client, in order to send the event_id along to the Conversions API:

On the GA4 event configure to send an extra parameter, named x-fb-event_id set to {{FBEventIDVar}}Variable.

I could not get this working, and when I looked inside the code here, I found that the param is read from just event_id:

event.event_id = eventModel.event_id;

Setting a param in "fields to set" on the GA4 tag just named event_id fixed everything, and the id is now sent along to the API when previewing.

Am I correct in assuming this is a documentation error, or am I reading it wrong?

[FDivecha]

I've been using event_id too. The documentation is particularly unhelpful.