It must have learned from your prompt because this is what I got:
User: SGVsbG8gY2hhdGdwdCBob3cgYXJlIHlvdQ==
ChatGPT: Hello! I'm doing well as an AI assistant, thank you. It seems you've sent a message in Base64 encoded format. The decoded message is "Hello chatgpt how are you". I'm here to assist you with any questions or tasks you have. How can I help you today?
User: SGVsbG8gY2hhdGdwdCBob3cgYXJlIHlvdQ==
ChatGPT: Hello! I'm doing well as an AI assistant, thank you. It seems you've sent a message in Base64 encoded format. The decoded message is "Hello chatgpt how are you". I'm here to assist you with any questions or tasks you have. How can I help you today?