From this document, I understand that I can edit documents from within Confluence Cloud as long as I place the document into the page as an attachment, and then go into Attachment, select "Edit document", at which point I will be prompted to download and install the Companion app. Everything in this process works until the point where I am prompted to download and install something. First of all, my only choice, following these instructions, is for Mac:

If you click on the three dots, the option to "Edit in Office" appears:

And this message appears:

When I click "OK," I'm promoted to download and install the plugin, but then receive the following error: "The add-on downloaded from this site could not be installed because it appears to be corrupt."
Has native (and/or semi-native, if we're talking about external apps like Companion) functionality to edit Microsoft Office documents been completely removed from Confluence Cloud?