In the video I forgot to mention the simplest way to create a transaction template.
Let's say that you already set the type, category and amount for the transaction where you pay a monthly subscription fee for an online course. You realize that you have to insert this transaction for each month. It is possible to duplicate the transaction but you can create a transaction template also. Select the transaction,
press the "Create transaction template" button,
and go to the "Transaction templates" tab and provide a group name! If the amount is expected to change in each month then write -1 000 000 into that cell to remind yourself that it should be modified.