Asking about the law, I learned:
1. If it is settled through negotiation, the buyer will bring the contract, etc. And negotiate with the developer to assume the liability for breach of contract. If there is little difference between the two parties, after reaching an agreement, the two parties will sign an agreement to stipulate the way to bear the liability for breach of contract and the final handling method, and the developer will compensate the buyer.
2. Send a lawyer's letter. If the buyer and the developer fail to negotiate, they can entrust a lawyer to send a lawyer's letter to the developer. The lawyer's letter can remind and warn the other party and urge the other party to take responsibility actively, which is much more convenient than judicial channels, but it is not mandatory. If the other party refuses to pay compensation, it will eventually need to file a lawsuit.