Using NEST

Hello guys I'm using version is elasticsearch 7.11 and NEST 7.0.0 / Elasticsearch.Net 7.0.0 in .Net stendard 2.0 Unity3D

but I can't used this client package because this error
" Assets\Script\BulkScript.cs(10,7): error CS0246: The type or namespace name 'Nest' could not be found (are you missing a using directive or an assembly reference?) "

I write "using Nest" but still that cannot used how can i do....