What libraries are being used to enable this? How would someone add this feature to their own website?
You don't really need a library. It's more so adhering to a protocol by running a service you make or someone else's. I wrote my own for SN. Here are the docs for it: https://github.com/andrerfneves/lightning-address/blob/master/DIY.md
A couple stackers have write ups on their own systems that they built so I'm hoping they chime in but given
<name>@stacker.newsthe gist is:GETrequest to stacker.news providing<name>GETto the URL from2with the amount from3Simply brilliant.
That's actually very elegant. Thanks for the helpful response.
If your looking for a simple NodeJS implementation checkout my repo: https://github.com/mefatbear/lightning-address-nodejs
Works with your own Umbrel / LND node.