OK, you can wait for the Zotero Connector update mentioned there, which should fix this, but as we say there, we can't guarantee that future updates won't break things.
For that and for security reasons, you should really switch to a browser that's still being maintained. For macOS 10.13, you can use the current Firefox Extended Support Release, which will support 10.13 through at least this later this year. The next Firefox ESR after the current one will require 10.15 or later.
Note that Zotero 7.1, coming soon, will also require 10.15, so you're going to need to switch to a newer computer to remain on supported software. I think you would have to be running a Mac that was (well?) over 10 years old to require 10.13. 10.15 runs on Macs dating back to 2012.
"cette nouvelle mise à jour": est-ce que vous voulez dire Zotero 7.1? La version finale n'est pas encore disponible mais il y a des versions de test sur https://www.zotero.org/support/beta_builds depuis déjà quelques semaines/mois. Cependant, comme l'a écrit le premier répondant, Zotero 7.1 (test ou définitif) ne fonctionnera vraisemblablement pas sur votre version de macOS.
I think @caroline.garcin just means the Zotero Connector update that will fix compatibility with old versions of Chrome. That's not yet available, but as I say in the linked comment, it should be available within a day.
Upgrade Storage
https://forums.zotero.org/discussion/comment/490442/#Comment_490442
For that and for security reasons, you should really switch to a browser that's still being maintained. For macOS 10.13, you can use the current Firefox Extended Support Release, which will support 10.13 through at least this later this year. The next Firefox ESR after the current one will require 10.15 or later.
Note that Zotero 7.1, coming soon, will also require 10.15, so you're going to need to switch to a newer computer to remain on supported software. I think you would have to be running a Mac that was (well?) over 10 years old to require 10.13. 10.15 runs on Macs dating back to 2012.
Cependant, comme l'a écrit le premier répondant, Zotero 7.1 (test ou définitif) ne fonctionnera vraisemblablement pas sur votre version de macOS.