my office wi-fi

Simply relying on the iPhone’s signal indicator is not helpful. I need to visualize the entire Wi-Fi network, identifying both weak and strong spots. I found free app to create WiFi heatmaps in my office https://apps.apple.com/us/app/netspot-wifi-map-speed-test/id1490247223. It does the job, but I’m wondering if there’s a better way to get more precise WiFi coverage measurements and export them to PDF? This app does not have any export features. My boss is really keen on reports. I’ve also heard that iPhones can’t perform this kind of measurement properly without additional hardware. Is that true?