If I have a flow that is triggered by someone purchasing a specific product
Is it possible to manually add a subscriber to a flow without them purchasing it in Shopify?
Best answer by retention
You can’t manually add a customer in a Flow that’s being triggered by an event (metric). There’s a way to add a customer in a Flow that’s being triggered by List. This means that you can re-create the same Flow, set it to be triggered by some List, and import that customer into the List. That will trigger the Flow.
Now, you need to remember that when Flow is triggered by an event (e.g. placed order), the metric used as a trigger passes certain data for the event, that you can use in the Flow. A good example would be when someone places an order. Among many other things, the event passes the Product Title, Price, Product Image, Quantity, etc. You can use all those things in the Flow that is triggered by the “Placed Order” metric.
If you decide to trigger the same Flow with a List, that data won’t be available.
Depending on your specific situation, if you want to use the data that is being passed from Shopify to Klaviyo through the metric into the Flow, you can’t trigger it manually. If your email(s) doesn’t use any of that data, you can go with re-creating the Flow and setting its trigger to be some List in which you can manually import contacts.
If this is a one time situation, you can even send the email(s) from the Flow as campaign(s).
Here are a couple of reference links: