Cannot run slack integration

[mepoohsta]

After run /slack/sign_in/check I have

Started GET "/slack/sign_in/check" for 46.53.243.48 at 2019-03-20 15:58:32 +0000
Processing by SlackSignInController#check as HTML
Current user: mepoohsta (id=1)
Completed 500 Internal Server Error in 6ms (ActiveRecord: 2.2ms)

UncaughtThrowError (uncaught throw #<ArgumentError: Required arguments :code missing>):
plugins/redmine_bots/lib/redmine_bots/slack/sign_in.rb:14:in call' plugins/redmine_bots/lib/redmine_bots/slack/sign_in.rb:4:in call'
plugins/redmine_bots/app/controllers/slack_sign_in_controller.rb:6:in check' lib/redmine/sudo_mode.rb:63:in sudo_mode'