Best Meta Ads objective for getting paid event registrations?

Hi everyone,

For those who have experience running Meta ads for paid one-day events or conferences, which campaign objective has worked best for you?

Engagement

Traffic

Leads

We don't have a website. We'll be linking people to a Linktree page that contains instructions on how to register. From there, users can choose one of three Google Forms:

Regular registration

Student registration

Group registration

This is my first time running a campaign with an objective other than Awareness. My goal is to get participants that can register and pay the event/conference fee.

Has anyone run a similar setup? Which objective would you recommend, especially if you're sending traffic to Linktree and Google Forms instead of a website?

Thanks in advance!