I have a problem with customers accessing the pay now for emailed invoices sent from my iPhone is it a setting or what is happening

Hi there, @scottkraley-gmai.

There is no additional setup when you process online invoices for your customers in QuickBooks Online (QBO). Once you had an online payment account and selected a payment type from the Online Payment section, then your customer should be able to pay the transactions online by clicking on the Pay Now button on their email.

If your customers are having a hard time accessing the Pay Now tab, they can try opening their email through a private window. Here are the keyboard shortcuts:

• Google Chrome: Ctrl + Shift + N
• Mozilla Firefox: Ctrl + Shift + P
• Microsoft Edge: Ctrl + Shift + N
• Safari: Command + Shift + N  

Please also make sure that their web browser is up to date.

If the error continues, they can right-click the Review and pay button in the invoice email and copy the URL. Open a web browser and paste the link into the address bar. 

For more tips about handling online payments in QBO, open this article: Take and process payments in QuickBooks Online.

When you're ready to enter the payments, use this link as your guide: Receive Payments QBO.

If you have any other questions about online invoices, let me know by adding a comment below. I'm more than happy to help. Keep safe!