Form settings → Google Maps browser key; calculation editor → Add a distance
Before you start
Use a Google Maps project with billing and the services required by your installed integration. Configure key restrictions for the real domain. An address label alone is not enough: identify address fields with Type of information.
Step-by-step instructions
Create the departure and destination fields. Set their information types to the corresponding address information and collect enough detail to identify each location.
Enter the Google Maps browser key in this form’s settings. Select the available distance mode and units appropriate to your rate; road and straight-line distances are different quantities.
Open the price calculation and use Add a distance to choose addresses and distance or travel-time information. Keep the token generated by the editor rather than typing IDs manually.
Build the rule as a base fee plus distance multiplied by your rate. For example, a 10 base fee plus 2.5 per kilometre gives 60 for 20 km, before other charges.
Check the result
Try two known addresses, a changed destination and an incomplete address. Verify the returned unit and that an unavailable route does not silently produce an accepted free quote.
If it does not work
Check the browser console for the exact Maps error, API enablement, billing, domain restrictions and quotas. If Add a distance is missing, check the form key and the address field information types.