[Feature] Custom URL for OpenAI-compatible API

[atmomomo]

Thanks for the great work. Is it possible to support custom URL for OpenAI-compatible API call? thanks.

Problem Description
The fixed API endpoint limits integration flexibility and branding opportunities for applications.

Proposed Solution
Please add support for custom URLs for API calls to allow integration with user-owned domains and paths.

Additional Context
This feature would enable secure, branded interactions with your API through a customized gateway.

---

问题描述
请描述您遇到的问题或难题，以及为什么这使得使用软件变得困难或令人沮丧。

解决思路
请提供一个清晰、简洁的描述，说明您希望看到的功能或解决方案。

附加上下文
请提供任何其他上下文或信息，以便更好地理解您的功能请求，例如截图、示例或用例。