Process completed with exit code 12.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

'JsonSerializerOptions.IgnoreNullValues' is obsolete: 'JsonSerializerOptions.IgnoreNullValues is obsolete. To ignore null values when serializing, set DefaultIgnoreCondition to JsonIgnoreCondition.WhenWritingNull.' (https://aka.ms/dotnet-warnings/SYSLIB0020)