Getting the following exception when trying to add service stack reference to PCL

Severity Code Description Project File Line Suppression State
Error Could not install package 'ServiceStack.Text 5.5.0'. You are trying to install this package into a project that targets 'MonoAndroid,Version=v7.1', 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. 0