In the same way as with shared and Cloud hosting plans, you can have your domains protected by SSL on VPS.
While it's recommended to consult the official documentation for the operating system and template of your server for specific instructions, you can find some useful guides here. There are free and paid options available:
Free SSL options
Some OS with control panel functionality have free SSL already available. You can check the guides below for the following operating systems:
For panels that don't have an SSL option, or if your OS does not have a panel, you can use Certbot.
Paid SSL options
You can also install any paid SSL certificate of your choice. If you prefer a paid option, such as Comodo SSL, you may refer to the installation tutorials from Comodo.