How to set referral code for an order?

[mb298]

Hello!

For order attribution, we are trying to set the referral code associated with an order, which can be retrieved using the admin graph API under: order -> customerJourneySummary -> firstVisit/lastVisit -> referralCode (documentation).

With vanilla Shopify, this can be done by setting a ref param to the url of the brand website. However, when using hydrogen, setting a ref param is having no effect on the eventual referralCode - customerJourneySummary does have a non-null firstVisit field, but the referralCode is empty.

I tried making sure that the referrer field is set under the payload of the https://monorail-edge.shopifysvc.com/unstable/produce_batch API. Although this affected other fields under CustomerJourneySummary, it does not seem to set referralCode.

Would appreciate any pointers on how to achieve this. Thank you so much!