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. 25-50 is one additional fee, 51-75 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!