You can access your server via SSH. First of all, you need to enable it. Please contact us for SSH info. We'll provide an IP and port number.
After that, you'll need SSH app installed on your computer. For PC, we do recommend Putty: https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html
For Mac, please consider Terminal application. Type the following command to login:
ssh youruser@yourdomain.com