Regardless if you are using IStringLocalizer, IHtmlLocalizer or IViewLocalizer they will run string.Format internally.
Localizer["Text {0} localized by {1}", "to be", "string.Format"]
This would print the text "Text to be localized by string.Format".
The Localizer can be nested as well.
// Info = "You can {0} your password or {1}."
// ResetPassword = "reset"
// Login = "select to login"
Localizer["Info", Localizer["ResetPassword"], Localizer["Login"]]
This would output "You can reset your password or select to login".
You can check even more tips and tricks in the documentation, https://docs.microsoft.com/en-us/aspnet/core/fundamentals/localization?view=aspnetcore-2.2
