Using active_record_store instead of cookie_store

I am using

intializers/session_store.rb
MyApp::Application.config.session_store :cookie_store, key: '_myapp_session'

config/application.rb
config.middleware.insert_before "ActionDispatch::Session::CookieStore","Rack::SSL"
config.middleware.insert_before "ActionDispatch::Cookies","Rack::SSL"

Now i want to use active_record_store for session, for which I made changes below

intializers/session_store.rb
MyApp::Application.config.session_store :active_record_store, key: '_myapp_session'
ActiveRecord::SessionStore.session_class = MyAppSession

not sure how to make configrations in config/application.rb
i want to make sure i should able to set_cookie: '_myapp_session' in response headers, fo which "ActionDispatch::Cookies" is responsible