Hi @Anonymous
it's not available anymore starting from revit 2017.
For the 2020 version you have the steel module integrated, with which you will have functions similar to the content generator, with respect to the Revit Extension it was also left out, it can be replaced with Naviate.
https://www.naviate.com/naviate-for-revit/product/naviate-rebar-extension/p-660
Jamhmer Oc