public static class Config
{
    public static IEnumerable<ApiScope> ApiScopes =>
        new List<ApiScope>
        {
            new ApiScope("api1", "My API")
        };
}

public static IEnumerable<Client> Clients =>
    new List<Client>
    {
        new Client
        {
            ClientId = "client",  
            // no interactive user, use the clientid/secret for authentication
            AllowedGrantTypes = GrantTypes.ClientCredentials,
            // secret for authentication
            ClientSecrets =  { new Secret("secret".Sha256()) },
            // scopes that client has access to
            AllowedScopes = { "api1" }
        }
    };