[ Unity ] 'Task<DependencyStatus>' does not contain a definition for 'ContinueWithOnMainThread' ..

에러문
'Task<DependencyStatus>' does not contain a definition for 'ContinueWithOnMainThread' and no accessible extension method 'ContinueWithOnMainThread' accepting a first argument of type 'Task<DependencyStatus>' could be found (are you missing a using directive or an assembly reference?)

해결: 스크립트에 아래 추가
using Firebase.Extensions;