My emailed invoices are no longer showing a way for them to pay online through quickbooks?

Thanks for letting us know, jms1_2000. I have the information that can help your customer pay their invoices online. Let me assist you in resolving this matter.

If the option to pay emailed invoices online isn't visible on your customer's end, payment processing transaction is an add-on through QuickBooks Payments. If subscribing to this feature isn't available in your business, you can still email invoices to your customers but they won't be able to pay directly from the invoice.

However, if you're using QuickBooks Payments, you can activate this first so they can see the Pay Now option on their emails and pay directly an invoice from there.

In addition to that, if your customer encounters an error when clicking the Pay now option, they can clear their web browser cache as this can help resolve issues with payment links.

I'm also sharing this reference for more detailed inputs: What to do if your customers can't pay their invoices online.

Furthermore, you can visit this guide to help add specific personalizations and information on your sales forms: Customize invoices, estimates, and sales receipts in QuickBooks Online.

I'll keep this thread available anytime you need additional assistance managing customer invoices in your account. Feel free to let me know in the comments below. Keep safe and have a good one.