Publii doesn’t have a native commenting system but has support for the Disqus comment system built-in. You’ll need to set up an account and get a shortname at https://disqus.com/. If you have coding skills you could look to add a different system, but it will take some work and a good understanding of what you are modifying.
Also, Publii devs are planning to introduce a plugin system with a future release which could open up more possibilities for comments without all the coding.
