Hi @digitalvapor

Don’t use the certificate you got from DNSimple, just create a new one directly on the server, so you also can setup the auto-renewal.

You can use this tutorial:
https://www.digitalocean.com/community/tutorials/how-to-secure-nginx-with-let-s-encrypt-on-ubuntu-16-04

But I think your Nginx file might be something different than /etc/nginx/sites-available/default, since you’re using the one-click, so check the folder /etc/nginx/sites-available/ for other configuration files.