invalid_client error during token exchange - clientSecret might need to be passed in request body

## Issue

Hello,

I am trying to configure the Oauth 2 flow for Whoop. The Authentication step works but hte tokenn exchange fails with the error invalid_client : Error: Client authentication failed (e.g., unknown client, no client authentication included, or unsupported authentication method).
Using postman, the flow works when the client id and secret are passed in the token request body and not as a request query parameter but I cannot seem to find the right parameters to pass in the config object to do so (if the error is even what I think).

I have looked on other issues, but can't seem to find the solution.

Thanks a lot for your time and help,

Best

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## Environment

* **Your Identity Provider**: WHOOP
* **Platform that you're experiencing the issue on**: both
* **Are you using Expo?** No

检查 WHOOP provider 的 OAuth 配置和令牌交换路径，重点关注 client ID 和 secret 的提供方式。复现 issue 中描述的失败，并将其与可正常工作的 Postman 请求进行比较。完成标准是确定受支持的配置，并且要么在 request body 中携带 credentials 后交换成功，要么记录该限制。

由索引模型根据 Issue 内容生成。