I'm not sure you can do this🤔
I think Alby used to let you send to an on-chain address. But that seems to have stopped.
I think I used muun to send to on-chain. But this may be a stupid solution and thing to do ¯\_(ツ)_/¯
Discussion
So what's the point of earning money here if it's locked in another layer?
I think the situation depends on a few things... how much you feel comfortable having in custodial lightning wallet, also some people do have non-custodial wallets.
I mean some people probably sell to buy stuff they need with $ too.