[Design Tokens] Text Styles?

There’s another post saying the typography.headings property can be used to modify the text styles in the editor using the design tokens. However, when I try this the entire typography section disappears from the Builder UI without any errors.

export const designTokens = {
  colors: [
    { name: 'PrimaryText', value: '#333333' },
    { name: 'SecondaryText', value: '#666666' },
  ],
  typography: {
    headings: {
      h1: {
        fontSize: '32px',
        color: 'var(--colors-primaryText)',
      },
      h2: {
        fontSize: '28px',
        color: 'var(--colors-secondaryText)',
      },
    },
  },
};

Is this valid? It’s difficult to find out what can and can’t be used as the docs are pretty sparse and there aren’t any TypeScript types for the tokens.