Maker's built-in testing and optimization tools enable you to easily create campaigns with multiple variants.
First, select the story to which you'd like to add a campaign. Then click on More Options > * Options > + Create Campaign.
After clicking + Create Campaign, the campaign specific modal will appear.
From the modal you can alter all of details of the test, including:
When your details are complete click Save.
Note: If the content is already live on your site, you'll need to re-copy and paste the embed code to include the campaign params. The only exception is if you're using Enhance, in which case you don't need to re-copy and paste the code.
After saving the details of your campaign, you will be directed to a confirmation screen with the unique URLS for each variant.
Note: After the embed code is added to your page with the campaign, a variants dropdown menu will appear on the page to the left of the EDIT STORY button, from where you can also grab the unique variant URLS.