Install binutils-mipsel-linux-gnu by entering the following commands in the terminal:
sudo apt update sudo apt install binutils-mipsel-linux-gnu
GNU binary utilities, for mipsel-linux-gnu target
This package provides GNU assembler, linker and binary utilities for the mipsel-linux-gnu target. . You don't need this package unless you plan to cross-compile programs for mipsel-linux-gnu and mipsel-linux-gnu is not your native platform.