Container API is built into Firefox, but for now you need to install a Mozilla add-on to actually use the feature: https://addons.mozilla.org/en-US/firefox/add

Container API is built into Firefox, but for now you need to install a Mozilla add-on to actually use the feature: https://addons.mozilla.org/en-US/firefox/addon/multi-account-containers/ https://addons.mozilla.org/en-US/firefox/addon/multi-account...