❔ JSON serialization nullable warnings (best approach?)

using System.Text.Json;

class FileVerification
{
    private readonly string quackenFilePath = @"C:\Users\maske\Documents\dev\CSharp\TelegramBots\quacken.json";

    private readonly JsonSerializerOptions _options = new()
    {
        PropertyNameCaseInsensitive = true
    };
    public List<QuackenJson> JsonReadWithSystemText()
    {
        using FileStream json = File.OpenRead(quackenFilePath);
        List<QuackenJson> token = JsonSerializer.Deserialize<List<QuackenJson>>(json, _options)!;
        return token;
    }
}