How to use the @uifabric/fluent-theme.FontSizes.size32 function in @uifabric/fluent-theme

fontWeight: 600,
        padding: 0,
        margin: 0,
        marginTop: '32px',
        marginBottom: '12px',

        selectors: {
          '&:first-child': {
            marginTop: 0
          }
        }
      },

      props.as === 'h1' && [
        {
          fontSize: FontSizes.size32,
          marginBottom: '28px'
        }
      ],

      props.as === 'h2' && [
        {
          fontSize: FontSizes.size24,
          marginBottom: '20px'
        }
      ],

      props.as === 'h3' && [
        {
          fontSize: FontSizes.size20,
          marginBottom: '8px'
        }

},
    isMountedOffset && {
      opacity: 1,
      transform: 'translate3d(0, 0, 0)'
    }
  ];

  const sectionStyles: IStyle = [
    {
      display: 'flex',
      justifyContent: 'center'
    },
    ...sectionAnimation
  ];

  const sectionTitleSize = FontSizes.size32;
  const sectionTitleStyles: IStyle = [
    {
      fontSize: sectionTitleSize,
      lineHeight: '1.1',
      marginTop: 0,
      marginBottom: '3em',

      selectors: {
        [mediaQuery.maxMobile]: {
          marginBottom: '1em'
        }
      }
    }
  ];

  const columnStyles: IStyle = [