After clicking on "Embed" and choosing "Follow Button Embed", you can configure the embed.

At the top you see the generated iFrame Code for your embed.

The Settings of the embed are structured in several tabs.

Here you can adjust the width of the embed. The height is adjusted automatically.

In the style settings, you can adjust the background shape and color.

Example:

Here you're able to define, if the magazine should be opened in fullscreen or on a new tab.