1. Click on 'Invoices'
2. Click on the invoice ID you want to open
3. Click on 'Receive Payment'
4. Here you can select the method used (Check, Cash, Zelle and more)
If you want to know how to add more payment methods Click Here
5. Make sure you select 'Method'
Here you will find the option to add a reference number, notes, indicate if the payment was a deposit, and also decide if you want to send an email receipt.