One ranking is an illusion. Google Maps shows different businesses at different corners of a city, so this scans a grid of points around you and shows where you are found and where you are invisible.
Most tools here fetch a page and analyse it. This one has to ask Google Maps what it shows from a specific street corner, once per point on the grid. A 5 × 5 grid is 25 lookups for a single phrase.
That means Google's own Places API (which has a free monthly allowance) or another paid ranking provider (scraping Maps, which breaks Google's terms and breaks whenever the markup changes). So the tool is built as an adapter: connect a provider and it returns real rankings; without one it tells you so and shows nothing.
A strong centre that fades to red is the "proximity halo": Google prefers businesses close to the searcher. Work the red zones with reviews from real customers there, local mentions and links, and a complete Business Profile. For a service-area business, the service areas you list move the pin, so list the towns you really serve. Run NAP Checker to confirm your name, address and phone agree across your own site first.