Sql Server Credential Manager

I am trying to add a new domain login to Credential Manager in Windows 11.

I have no problem adding a Sql Server credential such as myserver.internal.company.com

But if I try adding a named server such as myserver\instancename.internal.company.com I cannot add it. I have also tried 192.168.0.1\instancename, still cannot add.

How do I add a named instance int Credential Manager?  I cannot seem to find any help on this via a web search.

I can use runas netonly, no problem, but I would like to use Credential Manager.

Thank you for any help.