Native manifests describe where native messaging browser extensions can be found, as described here: https://developer.mozilla.org/en-US/docs/Mozilla/Add-ons/WebExtensions/Native_manifests#native_messaging_manifests Specifically on the MSIX version of Firefox available in the Microsoft Store, what directory does Firefox look in for native manifests? The problem I need to solve is that I need to place a native manifest in a location where Firefox can see it, specifically in the new Windows MSIX installer. This seems to be reasonably straightforward, if I can confirm where that is.