Each time you export references from a search tool, the newly imported references will appear in the "Recently Added" folder within your EndNote Desktop library.
Exporting from a Database: ProQuest as an Example
Ensure your EndNote Library is open
Go to a database of your choice, ProQuest as an example, and conduct a search on your topic
Select the references you want to export to your EndNote library
Click on at the top
Select "EndNote" from the Citation Export options. Different databases have different names for this exporting function, e.g. Send to; Export citation(s); Export; Export/Save; Save; Save to;EndNote [button]
Select the options shown below, check the box of reCAPTHCA, then click on "Continue"