https://github.com/WiringPi/WiringPi/releases
install method 1
Unzip/use the portable prebuilt verison:
# unzip the archive
tar -xfv wiringpi_3.0.tar.gz
Install the debian package:
# install a dpkg
sudo apt install ./wiringpi-3.0-1.deb
sudo apt install ./wiringpi_3.10_armhf.deb
sudo apt install ./wiringpi_3.10_arm64.deb ## install method 2
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i wiringpi-latest.deb
install method 3
sudo apt-get install wiringpi