By skyforbes ChatGPT used to provide an easy way to export individual chat conversations with a single click of a button. That button is no more in personal accounts. If you have a business account, you still need to make your conversation shareable to see the button.
I created a free bookmarklet that can export your conversations to PDF or HTML easily. I created it for myself so I can export some of my useful chats, which are brainstorming sessions, and put them on my blog. I thought it might be useful for others too: https://emrahdiril.com/chatgpt-export/