Hello! If you are looking for an alternative to ManyChat that does not have a limit on contacts for auto-reply and persistent menu features, you might want to consider using services like Chatfuel, MobileMonkey, or Dialogflow. These platforms offer similar functionalities to ManyChat and might meet your requirements.
If you are specifically looking for a PHP code for implementing auto-reply and persistent menu features, you can create a chatbot using PHP along with technologies like Facebook Messenger API or Telegram Bot API. Here's a general guide on how you can implement these features using PHP:
1. Set up a webhook: You need to create a webhook endpoint in PHP to receive messages from the messaging platform (e.g., Facebook Messenger). You can use libraries like Guzzle for making HTTP requests.
2. Handle incoming messages: Process incoming messages from users and implement logic for auto-reply based on specific keywords or triggers.
3. Implement persistent menu: Depending on the messaging platform, you can implement a persistent menu that allows users to access specific features or options easily.
4. Store user preferences: You can use a database like MySQL to store user preferences and provide personalized responses.
Please note that building a chatbot from scratch using PHP requires a good understanding of APIs, webhooks, and messaging platforms. You can find detailed documentation and tutorials on integrating messaging platforms with PHP to create chatbots. Let me know if you need more specific guidance or code examples!