https://learn.microsoft.com/en-us/dotnet/api/system.text.json.serialization.jsonderivedtypeattribute.derivedtype?view=net-10.0
JsonDerivedTypeAttribute.DerivedType Property (System.Text.Json.Serialization) | Microsoft Learn
A derived type that should be supported in polymorphic serialization of the declared base type.
property systemjson serializationtextmicrosoftlearn