Payment methods
To create your payment methods in erplain, please find the instructions on this page: Payment methods.
Payment accounts mapping
Once you have created your payment methods in erplain, you can map them with a QuickBooks payment account from Apps > Configure QuickBooks > Payment methods:
Payment accounts mapping
Once you have created your payment methods in erplain, you can map them with a QuickBooks payment account from Apps > Configure QuickBooks > Payment methods:

Payment methods mapping
You can also map your erplain payment methods with your QuickBooks payment methods. This can be done from Apps > Configure QuickBooks > Payment methods. Once the mapping is done, the chosen payment method will show in the QuickBooks payment.

Payments sync
Once an invoice as been synced to QuickBooks, the status of the invoice will be "Sent to QuickBooks" regardless of the payment status.
If you receive a payment in erplain, it will be synced to QuickBooks, and the payment will be assigned to the mapped ledger account.
If you create the payment in QuickBooks instead of erplain, the payment will not sync back to erplain but you can still check the QuickBooks status when you open the invoice in erplain:

Typically, customers receive payments in erplain so that it shows in both systems. In some cases, if you prefer to receive the payment in QuickBooks, this is not a problem but the payment will not show in erplain, only the QuickBooks status when you open the invoice.