You can use the same API key across all Pickaxes. But you have to enter it for each one. Here’s a walkthrough on API keys about how to find and use your own OpenAI API Key
Currently there is no way to globally apply an API key to all tools. The reason is because some users do utilize different keys for different tools.
If you are getting an error message it may have to do with models. Are you using an OpenAI API key? A Mistral API key? A different model?