Pop into Settings->Services & Fees:
Add modifiers to any service type for "Miles Away" or "Kilometers Away":
Keep in mind they are not cumulative, so you'll want to account for each range (i.e. 20-50 is one additional fee, 50-100 is another, etc., like in the image above.)
Also note these distances are from your company's address as listed in your Profile page. (This keeps the price consistent even if you multi-inspector companies change which inspector is assigned to the inspection.)
You'll now see these automatically utilized on your New Inspection Form and your Online Scheduler!