You can build a brief by telling the chat about your campaign. Start wherever you like. Paste product notes, describe the creators you want, or give it a budget.
Steps
Ask "help me build a new campaign" and tell it what you know.
The chat asks one question at a time for anything that's missing, with a recommendation you can accept in one click.
When it has enough, it asks Create this campaign? Click Create to save it as a draft, and it shows you a summary.
Keep going, or change any part ("make the deadline two weeks later").
Open the brief page to check it over and launch.
Good to know
The chat only saves what you've told it or agreed to. It may suggest ideas based on your past ads, but you decide.
It never launches a campaign. You launch it yourself from the brief page, at step 3, Preview.
You can also edit the brief on the page. Both show the same draft.