Add people to manual segment?

Thanks for reaching out about this.

Good news - you can add additional people to this manual segment. You can do this via a CSV import, or a workflow action in a campaign. It sounds like CSV is the most useful option for you, so you can find the steps to do this in our documentation here: https://www.customer.io/docs/journeys/manual-segments/#add-people-to-a-segment-csv

I hope this helps!