Please add the `OPENAI_API_BASE` environment variable for `method=megaparse_vision` that can be pulled into the megaparse_vision via API. Alternatively, consider adding LiteLLM SDK so I can easily switch between models and providers. example of the environment variable: ```bash export OPENAI_API_BASE=http://127.0.0.1:8080/v1 ``` Code example for SDK: ```python from megaparse import MegaParse from langchain_openai import ChatOpenAI from megaparse.parser.megaparse_vision import MegaParseVision import os model = ChatOpenAI(model="gpt-4o", api_key=os.getenv("OPENAI_API_KEY"), base_url=os.getenv("OPENAI_API_BASE")) ```