Is there a 3rd-party service that hooks into ChatGPT (or other comparable LLM) that gives you a link to a simple page with a prefilled prompt/conversation; with users not having to have an account with _anything_? (Goal is to generate a letter about a specific topic with some input from the person that's looking at the link.)
IMPORTANT:
1. Please only recommend things that you personally use, I can google myself.
2. It must be a hosted service that's ready to use (not self-hosted anything).