You can create Horizontal Timelines by different methods in the Post Timeline Plugin, which are mentioned below; 

Method 1:  #

In order to add a Vertical Timeline, Create a new Page and click on the “+” icon to choose a “Post Timeline Shortcode Generator”

Here you can add a Horizontal Timeline by hitting on the Add Shortcode Button. After clicking on the Button, A Post-Timeline modal appears. Now go to the POST UI tab, and select Horizontal. In the vertical template, you can select 5 different template variations to display on your website. 

Method 2:  #

In this method, you can use various page builders to include horizontal timeline shortcodes to generate cool horizontal timelines on your website. 

Simply choose your Page builder such as Elementor, Visual composer to add a post timeline.