The FromBodyAttribute attribute is used to indicate that a parameter must be deserialized from the request body.
[AttributeUsage(AttributeTargets.Parameter, AllowMultiple = false, Inherited = true)] public class FromBodyAttribute : Attribute
The FromUriAttribute and FromBodyAttribute are mutually exclusive. The FromBodyAttribute is not needed for complex types as they are deserialized from the request body by default. There can only be one parameter that is explicitly marked with the FromBodyAttribute attribute or which implicitly is deserialized from the request body.