Charateristic catalog for backorder in "manage characteristics catalog" S4HANA 1909

Dear expert,

I am studying functionality Backorder Processing (BOP) of Advanced ATP in S4HANA 1909 release.

I'd like to add new characteristics (eg. Request delivery date, company code…) to a characteristic catalog, so that they will appear for subsequent selection in the Select Conditions dialog in the Configure BOP Segment app.

However, we could not add new characteristics to Characteristics Catalogs with Catalog Use Type “Backorder Processing” via “Manage Characteristics Catalogs” app.

all the characteristics have been faded out and cannot be able to select anything unfortunately.

Would you please give us an advice to solve this problem? is there anything regarding missing authorization?

Thanks in advance!