Fresh ASP.NET Core API returns empty JSON objects

For some reason, Text.JSON doesn't serialize public fields as well, so they need to be properties. This solved the similar issue for me

In order for the JsonSerializer to be able to see and serialize your properties, they need to be public:

public int Id { get; private set; } //the setters can be private
public string Make { get; set; }
public string Model { get; set; }