GHA pass in environment variable to overwrite workspace env variable

I would like to pass an environment variable to the Terraform Cloud workspace.

Currently, I have set environment=dev but in the GHA i’d like to be able to overwrite this variable to prod for example.

I tried to run GHA with -vars-file but I get a " currently not supported" error.

What options do I have to enable overwrites? Subsequently, I’d like to overwrite things like instance type etc…