Go to menu/administration (in the top right corner of the screen):
At opened admin-panel click « Products » next « Add »and choose « Write-off » , if you have several sales points than choose required.
At the opened window date and time will be automatically pulled up, but you can change it, by clicking on it. Put: write off reason, title, q-ty.
To add more products, click on « + », at the end click « Save »