How to use the @uifabric/variants.addVariants function in @uifabric/variants

borderWidth: 1,
            textSize: 13.5,
            textWeight: 600,
            iconSize: 12,
            contentPadding: '0px 6px'
          },
          !props.circular && {
            minHeight: 26
          }
        ];
      }
    }
  }
};

addVariants(WordCustomizations.settings.theme);

textColorHovered: '#fff',
              textColorPressed: '#fff',
              iconColorHovered: '#fff',
              iconColorPressed: '#fff'
            },
          props.primary &&
            !props.disabled && {
              iconColor: 'white'
            }
        ];
      }
    }
  }
};

addVariants(TeamsCustomizations.settings.theme);

import { FluentTheme } from './fluent/FluentTheme';
import { FluentStyles } from './fluent/FluentStyles';
import { ICustomizations } from 'office-ui-fabric-react';
import { addVariants } from '@uifabric/variants';

export const FluentCustomizations: ICustomizations = {
  settings: {
    theme: { ...FluentTheme }
  },
  scopedSettings: { ...FluentStyles }
};

addVariants(FluentCustomizations.settings.theme);