You don’t need to compile, just treat the download as a binary:
~/Downloads> file balenaEtcher-1.7.9-x64.AppImage
balenaEtcher-1.7.9-x64.AppImage: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-linux-x86-64.so.2, for GNU/Linux 2.6.18, stripped
~/Downloads> chmod +x balenaEtcher-1.7.9-x64.AppImage
~/Downloads> ./balenaEtcher-1.7.9-x64.AppImage
Alternatively, you can either add a ppa for a deb repo or download a .deb and install locally: