What to use to get data from Jira Server in asp.net (C#) application?

What can be used to get issues, teams, users from Jira Server.
I am developing an application in ASP.NET (C#)

What official tools from Atlasssian can be used (besides the RESP API)?
Heard about the SDK, but read that it is for plugin development

Give detailed information please

Searching shows old pages like this : How to create a C# client with REST API | Jira | Atlassian Documentation
Linking to repos like this : Bitbucket, NuGet Gallery | Atlassian.SDK 13.0.0

Atlassian themselves have only provided a Java implementation: https://developer.atlassian.com/server/jira/platform/rest-apis/#jira-rest-clients

Linking to repos like this : Bitbucket , NuGet Gallery | Atlassian.SDK 13.0.0 - Is this the official SDK from Atlassian?