Maybe i should have asked sooner

var invoiceService = new InvoiceService();
    var invoice = await invoiceService.GetAsync(subscription.LatestInvoice.Id, new InvoiceGetOptions
    {
      Expand = ["payments.data.payment.payment_intent"]
    });

    var clientSecret = invoice.Payments.Data.FirstOrDefault()?.Payment?.PaymentIntent?.ClientSecret;

This was my solution if anybody from stripe sees this can you provide better answer ? And maybe update c# examples they are written in .net 6 we are getting .net 10 an you could also use minimal apis now to mimic node style