Here is how to undo your changes on a campaign in mailchimp
- First click on "Campaigns" item in the left sidebar menu
- Then click on the "WIP" campaign name in the campaigns list
- Next click on the "Edit design" button in the email preview section
- Then click on the "Button" block in the left sidebar blocks panel to add a new button element
- Then click on the "Undo" button in the top toolbar to view formatting options
- Finally click on "Save and exit" button in the top-right corner of the header to test your email
