Xero: Account type is invalid for making a payment to/from

Problem:

When posting a Sales Reconciliation to Xero, the following message displays:
Account type is invalid for making a payment to/from

The IdealposXeroAPI.log has the following line or lines:
20201230 09:51:01.7697    PostAllPayments Validation ERROR : Payment:1713001->Account type is invalid for making a payment to/from

Search for the Payment number (in this case 1713001) to get the Account code being posted to:
20201230 09:51:00.1290    PostTransaction Start : @PAYMENT@11 Dec 2020 10:09:44|1202001|1713001~2010|50^

This indicates that the Account code = 2010

Fix:

In Xero, enable payments for the Account: 
1. Select Accounting > Chart of Accounts
2. Select the relevant Account code
3. Tick Enable payments to this account and press Save.

- additional information provided by Bec