Do carbon taxes in place today apply to carbon embedded in imports?
I think the answer is generally/overwhelmingly "no" there usually not a embedded carbon (import) tax in most jurisdictions. A 2019 paper says:


  The idea of a BCA is not new. In the US, for example, lawmakers have tabled several proposals to introduce a carbon tax. So far, though, no country in the world has an operational BCA. 


Supposedly the EU Green Deal was supposed to include one, but I haven't followed the developments. (There have been arguments against it already. And the US has already threatened to retaliate should the EU adopt it.)