library not found for -lRCTGeolocation

The geolocation module isn't a part of the react-native core module anymore since de 0.60 version (cf: https://facebook.github.io/react-native/blog/2019/07/03/version-60)

For it, you have to replace with the https://github.com/react-native-community/react-native-geolocation and delete the RCTGeolocation on the Libraries folder of your xcode project