T-code: F-53 is Posting Outgoing Payments.
I'm showing an example as below.
Company code: 9700
Customer: 14454
Amount for deposit: 2021/03/02 KRW 100,000
Bank account: 28260015
1. All open Item selection.
1) Input & press "ENTER" key.
Document & Posting Date: 02.03.2021
Reference & Doc.Header Text: TEST
Bank Account: 28260015
Amount: KRW 100,000
Value Date: Same as Document & Posting Date, 02.03.2021
Customer Account: 14454
2) Choose an item which paid and find the balance is Zero between entered and assigned.
3) Click Simulate.
4) Check the balance and save the document.
5) Document 30000003 was posted.
2. Additional selections.
1) Input.
Document & Posting Date: 02.03.2021
Reference & Doc.Header Text: TEST
Bank Account: 28260015
Amount: KRW 526,467
Value Date: Same as Document & Posting Date, 02.03.2021
Customer Account: 14454
2) Select Assignment and press "Enter"key.
3) Input Document Number: 12003946 and click Process Open Items.
4) Choose an item which paid and find the balance is Zero between entered and assigned.
5) Click Simulate.
6) Check the balance and save the document.
7) Document 30000004 was posted.