By default, the auto sliding feature is enabled in Verticalis Slider. If you want to disable that because of any reason, then you can do that from settings panel of the slider. Here is the option to do so.
Go to “Slider Settings page” and find “Enable autosliding of slides” under Slider Box section on “Basic Settings” tab. Choose “No” to disable auto-sliding for Verticalis Slider. Here is the screenshot of the same.