get.acme.sh

1. Install from web: https://get.acme.sh

Install https://github.com/Neilpang/acme.sh

curl https://get.acme.sh | bash

or

wget -O -  https://get.acme.sh | bash

2. Or, install from Git hub:

curl https://raw.githubusercontent.com/Neilpang/acme.sh/master/acme.sh | INSTALLONLINE=1  bash

or:

wget -O -  https://raw.githubusercontent.com/Neilpang/acme.sh/master/acme.sh | INSTALLONLINE=1  bash