Since ages I have been using Duo Security‘s 2 factor authentication mechanism and like it a lot. It’s ease of use and offer of a free tier is perfect for my homeserver.
I never paid a dime to them. If you’re smart with how you use your free “credits”, you really don’t have to pay for the use of Duo when it comes to a self hosting situation with a limited number of users.
This was a very painless experiencing to setup, as I’m used to from everything Duo Security is offering. The documentation is very good and explains all the details you’ll need for a basic setup.
For anyone using either remote control protocol, this is something to look into.
Stay safe, use 2FA wherever you can 🙂