wix react-native-navigation版本2-Fab图标未显示在屏幕上

Question

Fab图标未显示在屏幕中。我已经按照以下V2文档添加了源代码。

  static get options() {
    return {
      topBar: {
        title: {
          text: "Collapse",
          color: "black",
          fontSize: 16
        },
        drawBehind: true,
        visible: true,
        testID: "addLiveSale"
      },
      fab: {
        id: "addLiveSale",
        backgroundColor: "blue",
        clickColor: "blue",
        rippleColor: "aquamarine",
        hideOnScroll: true
      }
    };
  }