Or is there platform one can buy and sell easily without passing rigorous payment system? Please share
DEX like Bisq is the closest thing to that.
Apart from DEX, he can maybe try the Currency Exchange section of the forum, although he has a very limited offer and it is difficult to find a match for what he wants. I would take a look at it anyway.
I've also heard that there is a bot on Telegram for buying and selling with LN, but I don't know much about it.