In my startup file this line “keyResolver.GetSigningKey(identifier)”, the identifier part is underlined in red and the error its giving me is “cannot convert string to system.identity.Model.Tokens.SecurityKeyIdentifier”
Can you please include the full code where you are using this? This could be a syntax or reference issue. In addition, if you could include a bit more information about the application and context about what you are trying to achieve could help as well.
Also, are you following a sample application?