Add photos and videos to albums on iCloud.com
In Photos on iCloud.com, click Photos in the sidebar to see your photos or videos grouped by time and location.
Select the photos or videos you want to add to an album, then click the Add button .
From the pop-up menu, choose the album you want to add your selection to.
If you want to add the photos or videos to a new album, you can select New Album and enter a name. Then click OK.