Show scene on top of "react native modal" ?

### Version
Tell us which versions you are using:

- react-native-router-flux v4.0.1
- react v16.8.3
- react-native v0.59.10

### Expected behaviour

Hi guys,
Is there any way to display a scene on top of "react-native modal".
I tried to use Lightbox but it doesn't work.
Thanks in advance.

### Actual behaviour

### Steps to reproduce
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### Reproducible Demo

Please provide a minimized reproducible demonstration of the problem you're reporting.

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