From here, you will need to add the event to the corresponding Facebook page that you want the event on.
You then need to select a Facebook category that the event would fall under:
Then select the tickets that you want available on the Facebook event:
From there, you can add the event to other pages, before selecting Create Draft Facebook Event.
Then, head to your Facebook Page to edit the event directly.
Once you've published the event, then your customers can buy tickets directly from your Facebook page.