Hello there, Samity. Let me share some information about missing payment options on your customer's invoices.

Please know that payment processing is an add-on through QuickBooks Payments. 

To have this option, you can consider signing up for QuickBooks Payments. If you have one, you'll need to turn it on so your customers can pay directly from an invoice. Click this article to learn more: Turn on online invoice payments in QuickBooks Online.

If you don't have one yet, you can check out this article: Sign up for QuickBooks Payments.

You can also visit this link to learn how to personalize and add specific info to your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.

Let me know if you have further questions besides missing payment options in QuickBooks Online. We're here to assist you 24/7.