1)

Click on "Add Step"

2)

Select "Inline Step"

3)

You are in Capture mode, select an element to open creator panel

4)

Select an element 

5)

Selected element comes up with step title popup

6)

Here, you can add or change step title 

7)

Scroll down to "Settings"

8)

Select this checkbox to enable "This step is optional" setting for this step

9)

After customizing everything, click on "Save"