Package I found: https://www.npmjs.com/package/@react-native-masked-view/masked-view

Css example in a minute: jsfiddle

I found this qustion, but he don’t resolve my problem: React Native – add a masked circle overlay over image

From the example it came out like this, but I get the opposite effect:

<MaskedView MaskElement={<View
              style={{
                  // Transparent background because the mask is based on the alpha channel.
                  Background color: transparent
                  flexible: 1,
                  justifyContent: 'center',
                  alignItems: 'center',
              }}
          >
              <View style={{
                  width: 30,
                  height: 30,
                  Background color: black
              }}></View>
          </View>} style={{
              ...styles.container,
              Background color: black
          }}>

          </MaskedView>

What did I do wrong and how can I fix it?