1. If you get "Image or Text Generation Error", it means you didn't enter OpenAI API Key yet.
2. Please check this FAQ to know the process to collect API Key from OpenAI website:
https://support.marketro.com/a/solutions/articles/13000101286?portalId=13000000343
3. Please check this FAQ to know the process to add the key into AI Prompt Ace:
https://support.marketro.com/a/solutions/articles/13000101287?portalId=13000000343
Here is video explaining more: