Hello,
The recent Colab extension does work in VS_Code, but not in Positron.
It seems related to the Jupyter extension that is not the same one as the one in VS Code.
Is there any workaround to use it?.
There is not currently a workaround, but we are tracking support for Colab in Support for Google Colab extension · Issue #10559 · posit-dev/positron · GitHub, if you'd like to add a 
or any additional info on your use case.