How to find and download a specific APK (com.android.calculator2) from a FAW device?

Device in question is a FAW (Full Android Watch): a watch running a full Android OS, not WearOS. It is a LEMFO LEMP running Android 9.1, and I'd like to give the calculator I have to another member of the FAW community: https://discourse.fullandroidwatch.org/t/round-calculator-from-faw-app-store/73203/11 I connected to the watch via USB tether. I started the calculator app and then I opened an adb shell and browsed a ps:

DMN_C16_TFT_PIX64:/data $ ps -A | grep calc                                                                                                                                                                                                 
u0_a52        4132   291 3957800 106124 0                   0 S com.android.calculator2

Based on this I'm hunting for the apk com.android.calculator2. I browsed the file system with Device Explorer in Android Studio. I've found this: First, it looks like to be a directory. If I double click to step into that directory: In any case if I try to download it, I get an error.

DMN_C16_TFT_PIX64:/ $ pwd
/
DMN_C16_TFT_PIX64:/ $ cd data
DMN_C16_TFT_PIX64:/data $ ls -al
ls: .: Permission denied

Where is that apk and how can I download it?