Thank you for posting to the Community, @kundanrrajput-gm.
I want to share some details about sending invoices without saving customer number. However, I'd suggest contacting the WhatsApp Support since they know how to change your preferred setting.
If you'd like to know more about sending invoices with WhatsApp in QuickBooks Online from a mobile device, take a look at this article: Send invoices with WhatsApp.
If there's anything else you need to know about sending invoices, feel free to comment anytime. I'm always ready to help you more. Have a great day.
