Chart.js charts are rendered on user provided `canvas` elements. Thus, it is up to the user to create the `canvas` element in a way that is accessible. The `canvas` element has support in all browsers and will render on screen but the `canvas` content will not be accessible to screen readers.
With `canvas`, the accessibility has to be added with ARIA attributes on the `canvas` element or added using internal fallback content placed within the opening and closing canvas tags.