1)

Click on "Add Step"

2)

Select "Inline Step"

3)

You are in Capture mode now, this mode enables you to select an element on this page

4)

Select an Element

5)

Selected element comes up with step title popup

6)

Here you can add or change step title and description

7)

Scroll down to "Settings"

8)

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

9)

After customizing everything, click Save