Hi Chris

In your Laserfiche Workflow that Forms is calling, right click on the white background canvas and select View Properties, or when you are at the  activity, on the right pane at the bottom click the View Workflow Properties and you will get a popup in the middle of the screen which has this on the bottom of it

Check the Started by Laserfiche Forms box and you get an additional set of token menus called Input Parameters which have the variables that you are looking for