Exactly the same as on LocalBitcoins. You deposit Monero into the wallet, post an advertisement, and when someone opens a trade, the requested amount is taken to escrow. After the buying party has marked the payment complete and the selling party has verified the payment, the seller can release the escrow. Seller cannot cancel the trade after the buyer has completed the payment, and should a dispute arise, LocalMonero staff will resolve it after considering evidence provided by trading parties.

You can check also out FAQ (https://localmonero.co/faq) and Guides(https://localmonero.co/start) to get more detailed info.