Whenever I send an invoice to a customer, there is no place that can pay the invoice. Help me for the importance?

Hii there, @binom99099-gmail. Having a convenient and accessible payment option for your customers is crucial. I'm here to help you.

If you are trying to accept electronic customer payments for online invoices and in-person sales, we can create and send an invoice to your customer. Where it allows them to pay you when they choose Pay Now right from that invoice. We'll need to have QuickBooks Online Payments (UK). Here's how to send an invoice: 

1. Click the + New Plus icon.
2. Select Create invoice.
3. Choose the type of payment you'll accept under Online Payment.
4. Enter the invoice details, including your customer's email address.
5. Press Save and send.
6. Review the invoice in the Send email window. Then, add any additional information to the subject line and body of the email.
7. Hit Save and close.

See this article for more details: Take and process payments in QuickBooks Online article. To record invoice payments, check out the Record invoice payments in QuickBooks Online article. 

You can only pull up the Open Invoices Report to see those who owe you money.

Take a look at the Run reports article for more details. I’m also adding the  Customise your reports in QuickBooks Online article that talks about filtering details for future reference.

Feel free to visit our Sales and customers page for more insights about managing your company's income and customers.

I want to make sure everything is taken care of for you, please let me know how it goes. Just leave a comment below, and I'll get back to you. Take care always.