If you are using an older device running Android 4.x (such as KitKat or Ice Cream Sandwich), standard installation methods will not work. However, there are alternative ways to get a Linux-like terminal environment on your legacy device. Why Termux Doesn't Work on Android 4

If you manage to upgrade your device's firmware or use a custom ROM (like a legacy version of CyanogenMod) that brings you to Android 5.0+, you can then install legacy versions of Termux:

The official Termux application has . From its initial release, Termux required at least Android 5.0 (Lollipop) because older versions lacked compatibility with modern system libraries (libc) needed for its package collection.

Since official support is non-existent, you can try these terminal emulators and Linux environments designed for older hardware: