Windows negotiate auth in Swagger UI

I have a new ASP.Net Core Web API which is using standard Windows Negotiate authentication. It all works fine in a browser etc. but via a central Swagger UI service where the spec is passed with the Swagger UI `url` query parameter, all "Try It Out" attempts fail as Swagger UI isn't doing Windows auth negotiation - it's not sending any of the usual headers. Strangely, I can't seem to find any instructions anywhere for making Swagger UI do this? I am using version 3.20.5.