Applying a transparent background to react native is simple. below is a code just similar to the normal css for html pages, but just that it contains the react native styling type.
backgroundColor: 'rgba(52, 52, 52, 0.8)'
a good example is below
<Box
flex={1}
backgroundColor="lightblack"
justifyContent="center"
alignItems="center"
style={{
backgroundColor: "rgba(52, 52, 52, 0.2)",
}}
>
<Spinner color="white" />
</Box>
