Ollama custom URL with basic auth

[agung2001]

Is your feature request related to a problem? Please describe.
I would like to use a custom URL for my ollama instance from my server : https://ollama.example.com
but it uses a basic auth token for the authentication process

VSCode extension such as continue.dev uses the same configuration : continuedev/continue#834 (comment)

"models": [ {
      "title": "TinyLLAMA",
      "provider": "ollama",
      "model": "tinyllama",
      "apiBase": "https://ollama.example.com",
      "requestOptions": {
        "headers": {"Authorization": "Basic bXl1c2VybmFtZTpteXBhc3N3b3Jk"}
      }
    }]

Describe the solution you'd like
I think adding an additional option to configure the fetch function will be very helpful

Describe alternatives you've considered
none

Additional context
none

[logancyang]

This one seems related and a prereq langchain-ai/langchainjs#6631