I would really love to use this add-on, since eBay has been ignoring user requests for this option for years. However, requiring the "Access your data for all websites" permission, which gives the add-on access to your usernames and passwords is a dealbreaker.

Reply to developer response: Thanks for the github link, but like most people, I am not able to read programming code, so it doesn't really help me. Even if I were able to verify what you say is true, it makes no sense to give any add-on that kind of access (except a password manager) - what if someone found a way to exploit it? It seems to me permissions should be configured in such a way that a plugin can check to see whether you're on a certain site without needing access to all your usernames and passwords for every single site you log in to.