As far as I know Poenix doesn't currently support ln url that have the @ address.

Phoenix also has you deal with your channels with Asinq so it's a little more complicated then a fully custodial wallet like Wallet of Satoshi.l that just freely let's you send and receive sats.

There is a minimum fee of like 3000 sats and a minimum of initial transaction of 10,000 sats(I think this was the case last time I checked) for opening a channel.

So for best results it's better to open a larger channel so you won't have to keep paying that fee unless you receive more than your initial channel opening.

It may seem complicated and not ideal to newer users with a small amount of sats... but I've been using it for about 5 months now after figuring it out and it's my main LN wallet I keep most my funds in.

A little long winded so if I lost you I apologise.