Can't find namespace Microsoft.OpenApi.Readers

[elaugier]

Hello,
I want use the MS OpenApi.Net library but I encounter a strange issue because when i try to create a new instance of OpenApiStringReader because i don't know in which namespace i can find the class...
When i read the source, seems that the class is in the namespace Microsoft.OpenApi.Readers.
I try to add the package via "dotnet add package Openapi --version 1.0.1" and when i try to build, i get an error.

I try to open my project by using Visual Studio to use object explorer to look after the class. I can't found the namespace

Could you explain to me how access to this namespace ?

Thanks for your help

[elaugier]

Sorry. I found that it was another package to add to my project Microsoft.OpenApi.Readers