Does not show insert reference bar

I have not edited references on my blog since before the block editor. Now I have uninstalled and reinstalled academic toolkit and am trying to use it with the block editor. The user interface shows the bar starting with Add Reference and ending with three dots, but the bar (a-d) for inserting references is not shown. I have not found any way to insert a reference. I have 1296 items in my list of uncited references and I can select the one I want to insert. I just cannot get it to insert into the block where my cursor is located. Thanks in advance for your help!