ChatGPT is quite good at creating PRDs.
All good PMs have a good PRD template that they start with, but using ChatGPT to create a PRD for a new idea, feature or product accelerates the process 10x.
Try this: go to ChatGPT (or Claude or whatever) and type in:
I want to create a web app prototype to validate an idea.
The idea is a web-based app to do <your idea idea>. Create a Product Requirements Document to cover this prototype.
What you get back isn’t perfect… but it’s a great tool for helping think through the problem and what might be required to solve it. It will give a quick sense of feasibility and complexity and help identify gaps in your thinking that you need to solve.