Unfortunately the new extension is effectively an entirely new implementation because the older extension you mentioned here was tightly coupled to code from Terraform v0.11 (it literally included transpiled versions of supporting libraries inside of it) and thus it isn’t able to support the Terraform language from any other Terraform version. The new design is different to allow it to be compatible with various different Terraform language versions, but work is still underway to reimplement various features, including this one.
I think the existing tracking issue for this feature request is the following:
I’d suggest following that issue so you can see updates as the editor tools team work toward implementing that feature. Thanks!