Nice add-on and finally the alternative of legacy TabGroups is almost here. Thanks for your effort.
However, hotkey Ctrl+E does not work as mentioned by others, maybe roll back to the original tab groups Ctrl+Shift+E (or customizable hotkey)? Also, I am not sure if I overlook something, but I see only export backup but no import from backup? Is it possible to import groups from TabGroups (the legacy one)?
I've added an option for setting a keyboard shortcut in v0.0.12. However, the necessary API is only implemented in Firefox 60, so you will need to update to the beta before you can use the new option.
You can only use shortcuts which are not used by the browser - Ctrl+Shift+E is already taken.
