Identity Server Getting "error": "invalid_scope"

I am getting error while trying to get token for my custom scope value.Below is My code snippet.

public static IEnumerable<ApiResource> GetApis() =>
        new List<ApiResource>
        {
             new ApiResource("ApiOne","ApiOne",new []{ "ApiOne"})
        };
public static IEnumerable<Client> GetClients() =>
        new List<Client> { new Client
        {
            ClientId="client1",
            ClientSecrets={ new Secret("secret1".Sha256())},
            AllowedGrantTypes={GrantType.ClientCredentials},
            AllowedScopes={"ApiOne"},
            AllowOfflineAccess=true,
            
        },
        };