ASP.Net Error: HttpContextBase does not contain a definition for GetOwinContext

sallmomar says:

CS1061 C# 'HttpContextBase' does not contain a definition for 'GetOwinContext' and no accessible extension method 'GetOwinContext' accepting a first argument of type 'HttpContextBase' could be found (are you missing a using directive or an assembly reference?)

SO: ASP.NET Identity - HttpContext has no extension method for GetOwinContext[^]

Apparently you need a Microsoft.Owin.Host.SystemWeb package.