 Sometimes you can't find an author for a source, and you might want to use the organization as author. To fix this in Zotero, select the item, and in the panel on the right, you'll see author, and that it has a field for last name and first name. You can change this to one single field. Just select the small little rectangle to the right of first, which is switched to single field. Then you can click in there, enter the organization's name, and that's it. To switch it back to first name and last name, you'll see that the single rectangle has now turned back into two, and you can select it again, and you'll have two fields again.