Sono sinceramente confuso sulla situazione del visto

Chongqing is one of the cities eligible for the 144-hour transit visa-free policy, which allows you to stay in Chongqing and surrounding areas for up to six days without a full visa, provided you're transiting to a third country. For multi-city packages that include Chongqing, our advisors can confirm the exact visa requirements based on your nationality and full itinerary.

Singapore passport no need visa for China up to 15 days. But my UK friend used the transit one for Chongqing and it was smooth. Just make sure your flight in and out is from different countries.