Is it made using the retrieval plugin (https://github.com/openai/chatgpt-retrieval-plugin https://github.com/openai/chatgpt-retrieval-plugin) and a custom knowl

Is it made using the retrieval plugin (https://github.com/openai/chatgpt-retrieval-plugin https://github.com/openai/chatgpt-retrieval-plugin) and a custom knowledge base?