This will need to call 👍

 private static async Task PrepareRequestBody(HttpContext context)
        {
            if (!context.Request.Body.CanSeek)
            {
                context.Request.EnableBuffering();

                await context.Request.Body.DrainAsync(CancellationToken.None);
            }

            // Always start at the beginning.
            context.Request.Body.Seek(0L, SeekOrigin.Begin);
        }

Then read the body without a using statement in a StreamReader otherwise this closes the stream and it can't be read again therefore you'd need new StreamReader(stream).ReadToEndAsync()