download latest release
https://github.com/mumumusuc/termux-flutter
https://github.com/mumumusuc/termux-android-sdk
wget https://github.com/mumumusuc/termux-android-sdk/releases/download/30.0.3/android-sdk.deb
wget https://github.com/mumumusuc/termux-flutter/releases/download/3.19.0/flutter.deb
apt install *.deb
termux-fix-shebang /data/data/com.termux/files/usr/opt/flutter/bin/flutter