The primer library is a storage for keeping user primers. The added primers are stored between UGENE sessions.
Go to the Tools->Primer->Primer library context menu to configure the primer library. The following window will appear:
Click the New primer button to add a new primer. The following dialog will appear:
Input the primer sequence and primer name and click on the OK button.
Select the primer and click the Edit primer button to edit primer.
Select the primer in the table (you can use Ctrl and Shift) and click Remove primer(s) button to remove primer(s).
To export primer(s) select it and click the Export primer(s) button. The following dialog will appear:
Select file and file format and click on the OK button.
To import primer(s) click the Import primer(s) button. The following dialog will appear:
Add files and click the Import button.