how to fetch current location of latitude and lontitude from xamarin map in xamarin ios

We are developing a iOS shopping cart application in c# and visual studio 2017 for xamarin, While connecting to map, i got a error like'a geolocation error occurred position unavailable', one more thing, i got another error, if i put 10000, its show like that error[position = await locator.GetPositionAsync(10000);=>cannot convert from 'int' to 'System.TimeSpan?' and if i put TimeoutInMilliseconds then i got error like position = await locator.GetPositionAsync(TimeoutInMilliseconds:10000);=>The best overload for 'GetPositionAsync' does not have a parameter named 'TimeoutInMilliseconds'] request you to help us to resolve this issue