No, you cannot target a specific person on Facebook using the platform's advertising tools. Facebook's ad targeting options are based on demographic and interest-based data, such as age, location, interests, behaviors, and other criteria. Advertisers can use this data to create targeted ads that are displayed to a specific group of people, but they cannot target individual users.
Additionally, it is against Facebook's policies to use its advertising tools to harass or target specific individuals. Facebook's Community Standards prohibit content that threatens or promotes violence, bullying, or harassment, and the platform has measures in place to identify and remove this type of content.
If you are experiencing harassment or threats on Facebook, you can report the content and the person responsible to Facebook's support team. Facebook has resources available to help users protect their privacy and safety, including tools to block and report other users, limit who can see your content, and control who can contact you on the platform.