script to detect a file from inserted usb and puts into a Variable

There is a same named log file that I have on my 2 different android phones. When I plug it into my computer, it appears in the media folder, For example the first android phone:
/media/F6BA-0AF5/folder/A.log
I want to put that into a variable to be manipulated.
A_log="/media/F6BA-0AF5/folder/A.log"

The second Android phone appears as:
/media/303F-630E/folder/A.log

Is there a simple way to do this? detect a log file in a unknown mount, and put it into a variable. I'm using linux mint.

Do you want this to be done automatically on mount?
Do you want to distinguish between 2 phones plugged in at the same time?

If not:

variable="$(find /media/ -name A.log)"

sure!

Alas, I don't know exactly...

You need to add a udev rule for your USB device that will trigger a script when you plug in the device. Have a look around for how to do that. udev will recognise the different phones from the hardware model, so you should be able to get the mount point or trigger different scripts depending on the model.