Determining the location of your project will be very useful to increase efficiency when determining the position of the addresses of all your stops. In addition, it will also establish the telephone prefix that you will see every time you want to add a telephone number (in your stops and/or vehicles).
If you want to define one or modify the existing one, you must follow these steps:
Go to the Project Settings tab within Planner
In the General section, go to the Project Location box and enter the desired location (for example, it could be Barcelona).
Click Update to finish.
Remember, entering the location of the project will affect all the plans that are included in that project (so you only have to put it once).