The End Conversation Flow step type is available for use in custom bots exclusively.  
There is no logical use case to include it in any feedback bot.

"End conversation flow" is the final step in any custom bot where you use it, preceding handoff from the custom bot to a human customer service agent or to some other bot.

Entering a message in the Bot Message field is optional but we recommend that you do so anyway. Options that you choose from the Placeholders shortcut menu can help you to populate and personalize your message with values from:
  • Helpshift system-default variables, such as {{user_name}} or {{issue_id}}.
  • custom issue fields (CIFs) that your brand has defined for its own purposes.
  • the received response to any API call that your bot submitted during a previous bot step.

The "End Conversation Flow" bot step type can perform any combination of the following actions:
  • assign the issue to a queue, a bot, or an agent
  • add a private note to the issue
  • mark the issue as resolved or rejected
  • update issue tags
  • update custom issue fields (CIFs)
    You can also update single line text type CIFs with the placeholders as shown in the below image.