Hi there, @AnnaN!
You can do this today, although you’ll need some help from your Salesforce team (if you’re not a Salesforce admin) to create a custom field on the User Object in Salesforce. The process is outlined in our knowledge base here. If you already have that set up, then it should be good to use in your flow now. The exact naming convention for the merge field will depend on the field you created in Salesforce. Note: After the field has been created, it can take up to 24 hours for the merge field it to surface in Groove because that's the interval on which the Groove <> Salesforce metadata refreshes, but you can also expedite that process by navigating to this link to manually force a metadata refresh if you want the field to show up ASAP.
Kenna Valdez, Manager, Customer Community, Clari