cannot download H5P content types in Pressbooks

I was able to download H5P content types for my first book in Pressbooks using my educational institutional account; however, when I started a second one, it didn't work. I'd activited H5P in Plugins, but when I tried "Add New", I got the message 'It looks like there are no content types installed. You can get the ones you want by using the small 'Download' button in the lower left corner on any example from the Examples and Downloads page and then you upload the file here."

I didn't see any download buttons on The Examples and Downloads page. I hadn't encountered such a problem with the first book. Please advise. Thanks!