Here's a good starting point:
Demo of publsp from both the LSP and client side to see the full workflow.
https://video.nostr.build/7dafc25555841801641fabe359e285be36e9f26096e45938a3e02d54a371dfa8.mp4
Discussion
Say I want to actually give liquidity? Any tool you can recommend for that?
You can do it on Magma and Lightning Network Plus but I personally avoid using them because they require accounts whereas their competitors don't
I'd like to see an open source alternative to those where you *don't* need an account
Am account like as in kyc account?
You can use publsp to sell liquidity
The advantage of a p2p #nostr liquidity marketplace is that anyone can build on it.
I'm currently working on a simple website that runs the customer backend of publsp to allow anyone with an internet connection and a wallet to purchase liquidity from LSPs advertising over #nostr.
Having an Umbrel/Start9 app for it would be fantastic for LSPs.