If for some reason you need to transform the keys to camel case you can use this
# config/environment.rb
Jbuilder.key_format camelize: :lower
Jbuilder.deep_format_keys true
If you are also rendering json elsewhere like for example, you'll have to look for alternative solutions.
render json: sample_response.to_json, status: :ok
One very ugly (but effective) way to do this for one-off situations is:
sample_response.as_json.deep_transform_keys! { |key| key.camelize(:lower) }