It seems some modules were not installed by you properly .
Please try installing googleplus :
ionic cordova plugin add cordova-plugin-googleplus --variable REVERSED_CLIENT_ID=myreversedclientid npm install --save @ionic-native/google-plus
open terminal navigate to your ionic project and then try running these commands :
when i want to create a reverse client ID, google asks me to add a sha-1 signing certificate and the package name. for the name of the package google says it is in the file AndroidManifest.xml.However is the file AndroidManifest.xml or how to have the reverse client ID ? http://prntscr.com/jlzlip