When you first log in to TM3 the second thing you should do is to set up your stock. This page should reflect the price list for your clinic. There are three different types of stock you can set up:
1. Consultancy - You can find out how to create a consultancy item via this article.
2. Physical stock item - You can find out how to create a physical stock item via this article.
3. Cancellation/DNA - You can find out how to create a cancellation/DNA charge via this article.
To set up your stock items go to Settings > Setup > Stock. There are three charges already created in TM3 which you can overwrite. You can see these three stock items in the image below. To edit one simply click on Edit.
This will then open the edit charge screen where you can overwrite the details with your own and then click on 'Update' when finished.