The dialog component is used for all modals. It renders on top of the rest of the app with an overlay.
You'll need to manage the isOpen state in a wrapper component of your own and pass in a function to be used to close the Dialog. For documentation purposes only we've created a mock State to handle this, but you should handle the state in the component you consume Dialog in or in a wrapper component.
A few considerations must be made to ensure your use of the Dialog component is accessible:
Always be sure to provide either aria-labelledby or aria-label to your Dialog component. In most cases you should use aria-labelledby and pass it the id of your Dialog.Header. If there is no text in your header, or you chose not to use a header, you can use aria-label to describe the purpose of the Dialog.
Be sure to pass a ref to return the focus back to once the Dialog closes via the returnFocusRef prop. In most cases this should be the element that opened the Dialog. If you decide to manage focus within your application and want to bypass Primer React Components from doing so when the Dialog closes, you can omit the returnFocusProp.
If you're running into z-index issues or are rendering the component inside of an absolutely positioned element, you can wrap your Dialog in a React Portal.