Facebook launched a tool called Manage Activity that lets you delete data that will no longer be viewable by other users. However, it will remain in the trash for 30 days. The data can be restored after 30 days.
- Open your Facebook account and navigate to the “Settings and Privacy”.
- Top on the “Activity Log” option.
- Choose “Trash” and see if there are deleted posts available.
- Simply click "Restore" if there are posts available. Otherwise, you should follow the above steps.
For more read - https://onlinegeeks.net/how-to-recover-deleted-posts-on-facebook/
