I'm definitely late, but it seems to me that the only problem with your URL is that you used &
instead of ?
at the beginning of your query string.
Try this one instead: https://docs.google.com/forms/d/e/1FAIpQLSesGYSZgzQfqLiZIfi2JlQFQ5ttatNMZ9U8gJNA8Xa8U1X9fw/viewform?entry.253064463=myCustomValue