Hello @mkt ,
The best way to do this is to create a new tag and tag users via CSV File.
Article from Intercom help center:
Can I update user data with a CSV import?
Yes. You can update values, and add new attributes for existing users. All CSV imports require you to have a column with user email addresses. A few things to note:
You can update the email of a user by sending the same user_id and different email address. We'll update the user with that user_id in Intercom to reflect the new email address.
You can't update the user_id by setting a new value for it and using the existing email address - that would create a new record.
If you use both user_id and email in Intercom, sending email in a CSV import is enough to match the user record in Intercom.
If you leave a field blank when updating existing columns, it will result in overwriting values to unknown .More information can be found here.
Let me know if you have any further questions about this topic, more than happy to help.