JsonPropertyNameAttribute is not supported record from C#9? [duplicate]

Answer 1

There are 2 ways (that I know of) to create a record, the below will hopefully solve it for you.

public record QuoteResponse
{
    [JsonPropertyName("quotes")]
    public IReadOnlyCollection<Quote>? Quotes {get; init;}
}

Answer 2

By default attributes on record parameters apply to the parameter. To make them apply to the property you have to prefix it with the property: attribute location:

public record QuoteResponse([property: JsonPropertyName("quotes")] IReadOnlyCollection<Quote>? Quotes);