Once you publish your bot, its public URL will work and you can send it to anyone and start collecting results.
You can always modify your bot and the new changes won't be published as long as you don't hit the Publish button again.
- Restore published version: drop your current changes and revert the bot to its published version.
- Close zapbot to new responses: close your zapbot and your users will see the following message: "This bot is now closed."
- Unpublish zapbot: mark the zapbot as unpublished and your users will see the following message: "The bot you're looking for doesn't exist"