Under Accounting - Journals - Create Journal, enter the account that is linked to the automatic coding in the account column (A/C No.).
A message informs you that there is an automatic coding linked to the account. Click OK if you want to use it. See below.
The rows of the journal are automatically populated with the calculation from the automatic coding. See below.
Fill in a contra account, Description and Date. Then click Post. The journal may look something like the one below.