Does this plugin work with FSE/Block themes?

Hi,

At the moment, there is no lang-switcher block created for this type of themes.

However, you can use the floating language switcher instead (it has a classic drop-down or ascend function depending on where is positioned), or the shortcode [language-switcher].

As more than 5 days have passed since my colleague have responded, I will close this ticket as resolved, if you still want us to take a look, please let us know by creating a new ticket.