Click Turn on your AI agent: the creation of your agent opens. Follow its steps up to Launch my agent. Everything is already filled in from your sign-up, you only check it.
Before connecting, check that this browser is signed in to the LinkedIn account your agent should write from: the connection uses the account open in your browser.
Closed the checklist? The same button is in the EngageFast panel: click the orange button on the right edge of LinkedIn, then Turn on my AI agent.