Use Bootstrap’s custom button styles for actions in forms, dialogs, and more. Includes support for a handful of contextual variations, sizes, states, and more. Bootstrap includes six predefined button styles, each serving its own semantic purpose. To learn more about buttons in Bootstrap 4 Click here to know more.
In need of a button, but not the hefty background colors they bring? Replace the default modifier classes with the .btn-outline-* ones to remove all background images and colors on any button.
To make button rounded add .btn-rounded class..btn-rounded*