Error in Adyen.Model.AcsWebhooks.ChallengeInfo.FlowEnum Parsing, Authentication Webhook send a not existing value

[cedricmeleard]

Describe the bug
The SDK (v25+) is unable to parse the Authentication webhook from Adyen. Specifically, it fails to handle the challenge.flow field when the enum value is "PWD_OTP_PHONE_FL", as this value does not exist in the SDK.

Example of failing payload part:

"authentication": {
    "acsTransId": "03d1c58f-de0a-4443-85db-eda58a0f9a7b",
    "challenge": {
        "flow": "PWD_OTP_PHONE_FL",
        "lastInteraction": "2025-01-15T23:00:12+01:00",
        "phoneNumber": "*****4770",
        "resends": 1,
        "retries": 1
    }
}

SDK Reference
In SDK v27.0.0, the Adyen.Model.AcsWebhooks.ChallengeInfo.FlowEnum enum is defined as follows:

 [JsonConverter(typeof(StringEnumConverter))]
        public enum FlowEnum
        {
            /// <summary>
            /// Enum OTPSMS for value: OTP_SMS
            /// </summary>
            [EnumMember(Value = "OTP_SMS")]
            OTPSMS = 1,

            /// <summary>
            /// Enum OOB for value: OOB
            /// </summary>
            [EnumMember(Value = "OOB")]
            OOB = 2
        }

The PWD_OTP_PHONE_FL value is missing from this enum, causing parsing failures when such webhooks are received.

To Reproduce

1. Activate the Authentication webhook in the Adyen platform.
2. Send a test webhook containing a challenge.flow value of "PWD_OTP_PHONE_FL".
3. Observe the failure when the SDK attempts to parse the payload.

Expected behavior

The SDK should properly parse the challenge.flow value without error, including support for "PWD_OTP_PHONE_FL".

Additional context

This issue is reproducible on the N2F account.
Please investigate adding support for the missing value or a fallback mechanism to prevent parsing errors.