Copy and Paste Steps:
wget https://github.com/wkhtmltopdf/packaging/releases/download/0.12.6-1/wkhtmltox_0.12.6-1.bionic_amd64.deb
sudo apt install ./wkhtmltox_0.12.6-1.bionic_amd64.deb
wkhtmltopdf --version
wkhtmltopdf http://www.google.com.ph google.pdf