[shlomif@telaviv1 bookmarks-manager]$ web-ext sign ...
Applying config file: ./package.json
Building web extension from /home/shlomif/Download/unpack/to-del/bookmarks-manager
Server response: You do not own this addon. (status: 403)
FAIL

o: The extension could not be signed
    at /home/shlomif/Download/unpack/to-del/bookmarks-manager/node_modules/web-ext/dist/webpack:/src/cmd/sign.js:139:15
    at process._tickCallback (internal/process/next_tick.js:68:7)

[shlomif@telaviv1 bookmarks-manager]$