Maps on mission planner

i need to know how i can save google maps so i can use them for offline mission planning.
i found the folder where they are supposed to save at home/apmplanner2/mapcache
how do i download the maps or do anything for offline useage
im using ubuntu mate on my raspberry pi with the pi software downloaded here.
ive readed posts saying do right mouse click on the map location and save them
only 3 options there Go to here go to here alt and point camera here
can some people help me

ty in advance

If you click the ‘cache’ button in the bottom toolbar under the map, it will give you instructions.

Use ‘SHIFT or ALT and left click to select a region’