I am using firefox not standalone and I am having the same problem. No icons showing for adding to library. Followed the instructions further up this post to get a debug ID which is D1632642442.
Run through these. If none of that works, please provide all the information under step 11
https://www.zotero.org/support/troubleshooting_translator_issues
Any ideas?? I really need this!
https://www.zotero.org/support/troubleshooting_translator_issues