How to check if a marker is in a region?

Question

JavaScript

e.g. coordinates of the current visible region

{
  latitude: 41.0518849479476,
  latitudeDelta: 6.549058249078342,
  longitude: 3.571327558440175,
  longitudeDelta: 5.401477685996724
}

and marker coordinates

{
  lat: 38.9627135,
  lng: 1.2207056
}

how to correctly check that this marker is in that region?
an example of how it looks in the application, marker and region prntscr.com/iiqh3o
any methods are needed, but in general the map and markers are used from the react-native-maps module