Can anyone tell me how to configure online payments? I can´t see the option "payments" on my left menu. Please any help?

Hello, hola-blackpumadi. 

Thank you for reaching out to the Community. The possible reason why you're unable to view the online payment option could be the company you're located in is not supported by QuickBooks Online Payment. QB Payments only supports the QBO US version and CA version. 

You may consider utilizing a 3rd party app payment processor to integrate with QuickBooks Online. 

To know how receiving and recording invoice payments work, see this article: Record invoice payments in QuickBooks Online.

For future reference, adding some links which you may find helpful: 

• Record a customer refund in QuickBooks Online
• Void or refund customer payments in QuickBooks Online 

The Community is always here to help you if you have other concerns. Have a great day!