Programmatically add tag to las item saved

[alphonse.rou...@gmail.com]

I am using firefox & zotero connector, v5.0
I would like to add a tag to the last item scraped (item.tags.push(tag)) using the function scrapeThisPage from browser.js as soon as the function has completed. Adding code just after if(page.translators && page.translators.length) {} ensures that the call is made when the saving completed. However, I do not know how to access to some kind of lastitem property from there.
Can anyone help me ?