You would need a Token from OpenAI in order to use the MyndGen tool. You cna get a free key when you sign up here – https://openai.com/
Tokens are the basic unit that OpenAI GPT models (including ChatGPT) use to compute the length of a text. Tokens can be thought of as pieces of words. Before the API processes the prompts, the input is broken down into tokens.
Token usage is relatively light and you can find a total usage count via settings (gear) icon.