Hi @Netquatt,
Thank you for sharing this question with our Klaviyo community.
At this time, you can only integrate a single Facebook Ad account per Klaviyo account. In your account, you will see the drop-down to select an account to sync with. You can only choose one at a time.
You would need to create a new Klaviyo account for each Facebook account that you want to integrate with. However, you can use the same login email for each one, so you can quickly switch between them (read more about that here).
You can also share templates and flows between accounts (read more about that here).
Thanks for being a member of our community.