Hook, on the left-hand side of FltPlan Go, there is a menu when the program opens. When using the app on a tablet, the far left (black background) menu begins with an icon titled FltPlan.Com. Clicking on that icon brings up the main FltPlan menu on the left (white background). When using a computer to access the FltPlan website, the menu with the white background opened immediately. Whether on a tablet or computer, towards the bottom of the main menu is a tab called "Pilot Resources". The drop-down menu includes a link for "Chart Finder". Open that and insert the Departure and Arrival airports.
I had originally registered in the program when I downloaded the app on a tablet. Because I use a small tablet, I pulled-up the FltPlan website on the computer, signed in, and accessed the Chart Finder service as described above.
Departure: KCQB Arrival: KAHH will give you a good rendition of capability.