How to export your Facebook posts:
Navigate to Settings on Facebook.
Navigate to the section Your Facebook Information. Click on the ‘View’ button, followed by the ‘Transfer a Copy of Your Information’ line.
Please keep in mind that you are not’moving’ or ‘deleting’ old posts, as Facebook warns you. You are simply copying them to a different location. You must delete all of your posts manually, or you can delete your entire Facebook account.
Now, on the resulting screen, you can choose whether to save Posts, Notes, or Photos, or whatever else you want to transfer.
Please keep in mind that the posts you’re saving are only from your own profile.