What is the file format of the icons? What kind of library—a Creative Cloud Library or the traditional InDesign library (INDL)? What version of InDesign are you using?
Hello, the format of the file is .ai and the document is stored in Creative Cloud Library (I am using InDesign CC 2017)
Open the icon set into Illustrator. In Illustrator, open the Library panel (Window > Libraries). Create a new library (choose Create New Library from the library panel menu). Drag each of the individual icons into the library you created and give them a name. As you see below, check Graphics as the category.
In InDesign, open the CC Library (Window > CC Library). Open the library you created. Right/Control-click on each icon you want to add to InDesign and choose Place Copy.
It will be placed into InDesign:
Thanks a lot your your detailed explanations and screenshots