The window of the "Estimate" section is divided into two parts. The tree structure of the catalog is located on the left, and the right part of the window contains sheets with lists of positions that are already involved in the project.

To add an item to the project, find it in the catalog, and click the plus sign next to its name.

Under the status circles, to the right of the "Search" field, there is another "plus" symbol. By clicking on it, you can create a new position in the project without accessing the catalog.

Note that the three numbers next to the name of the item in the project show: the stock balance; the number of units added to this estimate; the current catalog price.