These are the steps to add parts to the library into Eagle
Note: Make sure that your Eagle Software is connected in your Tools tab.
The minimum Eagle version that the App supports is Eagle v8.
Open SnapEDA Desktop App
Search and click the part that you want to download
Then click Add to Library on Eagle
After a few seconds, Eagle will automatically open and it will open a Schematic
Click Add Part
If it's the first download, make sure to click Open Library Manager.
Go to In Use tab
Go to C
:\Users\<Username>\Documents\EAGLE\librariesand then choose SnapEDA Library.lbr
Locate the SnapEDA Library and see that it shows the downloaded libraries