How to use the ol-mapbox-style/stylefunction function in ol-mapbox-style

export function clearStyleFunction(def, vectorStyleId, vectorStyles, layer, state) {
  var styleFunction;
  var layerId = def.id;
  var glStyle = vectorStyles[layerId];
  var olMap = lodashGet(state, 'legacy.map.ui.selected');
  if (olMap) {
    lodashEach(olMap.getLayers().getArray(), subLayer => {
      if (subLayer.wv.id === layerId) {
        layer = subLayer;
      }
    });
  }
  styleFunction = stylefunction(layer, glStyle, vectorStyleId);
  if (glStyle.name === 'Orbit Tracks') {
    // Filter time by 5 mins
    layer.setStyle(function(feature, resolution) {
      var minute;
      var minutes = feature.get('label');
      if (minutes) {
        minute = minutes.split(':');
      }
      if ((minute && minute[1] % 5 === 0) || feature.getType() === 'LineString') {
        return styleFunction(feature, resolution);
      }
    });
  }
  return update(vectorStyles, { layerId: { maps: { $unset: ['custom'] } } });
}

layer = subLayer;
            }
          });
        }
      } else {
        lodashEach(layerGroups, subLayer => {
          if (subLayer.wv && (subLayer.wv.id === layerId)) {
            layer = subLayer;
          }
        });
      }
    });
  }

  // Apply mapbox-gl styles
  styleFunction = stylefunction(layer, glStyle, vectorStyleId);
  // Filter Orbit Tracks
  if (glStyle.name === 'Orbit Tracks') {
    // Filter time by 5 mins
    layer.setStyle(function(feature, resolution) {
      var minute;
      var minutes = feature.get('label');
      if (minutes) {
        minute = minutes.split(':');
      }
      if ((minute && minute[1] % 5 === 0) || feature.getType() === 'LineString') {
        return styleFunction(feature, resolution);
      }
    });
  } else if (glStyle.name === 'SEDAC' &&
    ((selected[layerId] && selected[layerId].length))) {
    const selectedFeatures = selected[layerId];

.then((glStyle) => {
    stylefunction(layer, glStyle, 'states');
    if (map.getLayers().getArray().indexOf(layer) === -1) {
      map.addLayer(layer);
    }
  });

this.getMapboxGlStyle(layerOptions.mapboxStyle.url).subscribe(res => {
        stylefunction(layer.ol, res, layerOptions.mapboxStyle.source);
      });
    }