Bug Description

I used fiber v3 client and used the SetProxyURL method. But the agent didn't actually work.
I checked the source code of fiber. SetProxyUrl sets the proxyURL for the Client, but this attribute is not used in the actual request.

How to Reproduce

Steps to reproduce the behavior:

1. just create a client , and SetProxyURL.
2. request
3. No proxy used

Expected Behavior

The set proxy should be used when making requests

Fiber Version

v3.0.0-beta.3

Code Snippet (optional)

No response

Checklist:

• I agree to follow Fiber's Code of Conduct.
• I have checked for existing issues that describe my problem prior to opening this one.
• I understand that improperly formatted bug reports may be closed without explanation.