Creating a {{my.line-break}} Token

In a few sessions at 2019 Summit, there were recommendations of how to set up UTM parameter history campaigns to track the multiple campaigns that are contributing to driving leads. In the screenshots shown, in the flow steps to add a new field value similar to {{system.dateTime}}: {{lead.utm_campaign}} {{my.line-break}}. I've searched and cannot seem to find clear direction on how to create a token for the line-break. Without this, my history fields aren't cumulative and keep overwriting. Anyone have clear instructions on how to set up the line break token in this program?

Thanks!

Jenn

@Karen Vuong​ @Hayley Iacocca​