Save lights, models, cameras etc to library

Hi Cyril,
Thank you for your reply! The following pages from adobe documentation lead me to believe otherwise.https://helpx.adobe.com/substance-3d-stager/interface/assets-panel.html
Is there a page that describes precisely how to save the various elements to the library? I notice there are button next to elements like colors that will directly save to the library as well as clicking the plus sign at the bottom of the library panel but it seems hit and miss and could use some clarity on how to save the various types of scene elements. Did not find any details in the documentation, so appreciate the extra help.

Thank You!