In Rocketship, you can set a Text UDF in a Ticket via a Published Workflow note.
To configure this:
As a reminder, per Datto Autotask best practices, Rocketship only synchronizes your UDF definitions once per day. If you add a new UDF, or edit the definition of an existing UDF, and would like to accelerate the local update in Rocketship to make the UDF available in your settings, be sure to Force Cache Refresh.