[https://certbot.eff.org/all-instructions](https://certbot.eff.org/all-instructions)
4. Install NodeJS 8.x (current LTS):
[https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions](https://nodejs.org/en/download/package-manager/#debian-and-ubuntu-based-linux-distributions)
- 5. Install yarn:
+ 5. Install yarn, and be sure to have a recent version (>= 1.5.1, the latest release):
[https://yarnpkg.com/en/docs/install#linux-tab](https://yarnpkg.com/en/docs/install#linux-tab)
6. Run: