Chef vault referring to rubygems.org

chef-vault cookbook is looking for gemfile from rubygems.org.
We want that it should not connect to http server and refer to local path.

how can we modify this in chef-vault cookbook.
currently the gemfile is like:

source ‘https://rubygems.org

gem 'tomlrb’
gem 'rake’
gem 'stove’
gem ‘community_cookbook_releaser’

Now this source needs to be changed.
how can we do this

The cookbook doesn’t use the gemfile. You should set up a local mirror for your rubygems and then set rubygems_url in your client.rb - see https://docs.chef.io/config_rb_client.html for more information.
Note that new releases of the chef client include the chef-vault gem by default.

Scenario is that we are using chef-vault cookbook but it refers to rubygems.org
In our environment , we cannot connect our servers to external server like rubygems.org.
we need to modify the chef-vault cookbook so it gets the gems installed locally.
How can we do this?

i changed the source path to my own http server and kept gemfiles on the http server. but when running chef-client on node it refers to rubygems.org instead of my specified path in gemfile. do i need to change anywhere else.

i also tried using rubygems_url in /etc/chef/client.rb but that also does not works .

i am working on chef-client 13.6.1