Hover your mouse over the field you will use to trigger a section to appear ('Incident Type' in this example). Click on More Options [⋮] and copy the Field ID:
Go to the section that you want to trigger to appear on your form if 'Storm' is selected as the incident type.
Hover your mouse over the Section title bar. Click on More Options [⋮] and Show based on a condition...
Type the following into the expression box:
thisDocument.data.incident_type === 'storm'
You can paste in the Field ID you have copied from the field that will trigger the section to appear, in this case incident_type. 'storm' = different_option_id; is the selection that will trigger the section to appear.