Error trying to install Autofac in Xamarin Forms project

[jloza...@gmail.com]

Install-Package : Could not install package 'Autofac 4.6.1'. You are trying to install this package into a project that targets '.NETPortable,Version=v4.5,Profile=Profile259', but the package does not contain any assembly references or content files that are compatible with that framework. For more information,
contact the package author.
At line:1 char:1
+ Install-Package Autofac -Version 4.6.1
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ CategoryInfo : NotSpecified: (:) [Install-Package], Exception
+ FullyQualifiedErrorId : NuGetCmdletUnhandledException,NuGet.PackageManagement.PowerShellCmdlets.InstallPackageCommand

someone help me!!!