Hi,
This can be achieved with a ChatGPT API Key - you are most likely going to need to pay for ChatGPT Premium, otherwise you'll soon rinse the API call credits.
Then, you could use the "GPT3 Completes your prompt (preview" Premium action in Power Automate, and call this flow in your Power Pages. It would need to be passed raw text questions, so ensure that you remove HTML formatting (if necessary), as a previous step.
K.