https://addons.mozilla.org/en-US/firefox/addon/profile-switc...
You'll need to install a connector for it to work. (The add-on gives instructions during the onboarding process.) Both the add-on and the connector are free and open source (GPLv3).
I use profiles and containers together on Firefox. Each profile has its own set of add-ons, browser settings, and containers. Containers in the same profile share the same add-ons and browser settings. For example, you could have separate personal and work profiles, with containers for different online accounts in each profile.
On Firefox, you have the option of using only profiles, only containers, both profiles and containers, or none of the above.