Just create the test, write the 2 content versions to test, set the target checkpoint URLs and publish the module/plugin: DM A/B Test will split the 2 content versions among your visitors and keep track of their passage on the checkpoint URLs (for example your checkout page).
You'll be able to check the results of your tests, tracking the percentage of visitors that passed through each checkpoint depending on the content they saw.
For example: in your front page, create 2 versions of the call-to-action module, anche check which one converts more; or, in an e-commerce website, check whether showing testimonials in each product page means more sales or not...
There was an issue on my website that to do with j3.3.6. I had to give them access to look into it. After that, they offered a new upload of the package and I could use it like I want too.
I now am able to A/B test all on my website, articles, images ,modules placements.