Thanks for making an AppImage. As far as I know, this is the first Flutter-based AppImage out there in the wild.
me@host:~$ ./Downloads/Otter_Store-x86_64.AppImage
AppRun AppRun-x86_64 otter_store.desktop otter_store.png usr
/tmp/.mount_Otter_1vVa1t/usr/bin/otter_store: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.29' not found (required by /tmp/.mount_Otter_1vVa1t/usr/bin/../lib/libgtk-3.so.0)
This happens because the binaries that go into the AppImage have been compiled on a system newer than the system I am trying to run this on (in my case, 18.04). I think it would be worthwhile to have a version that is compatible at least with all still-supported releases of Ubuntu (and other distributions of similar age).
Would it be possible for this to be compiled on Ubuntu xenial (currently the oldest still-supported release), e.g., using Travis CI or GitHub Actions?