When adding transactions manually in QuickBooks Self-Employed, you'd want to make sure to include the amount and description. Let me guide on how it works.
Go to the Transaction menu
Choose the Add Transaction button.
Enter the amount and a description.
Click the Select a category menu.
Assign the best category to organise your transaction.
If you have a receipt, you can drag and drop it onto the form.
Hit Save.
Also, I'm adding these articles to help you manage your transactions: