Pixelfed has a facility to import images from your Instagram account.

Your admin may have disabled this feature, as it is very resource intense. If available, it will be under Settings, Import

• Download your information in Instagram's Accounts Centre at https://www.instagram.com/download/request. Make sure you select the JSON format
• Wait for the email from Instagram with your download link
• Download your .zip export from Instagram and extract the Zip on your computer.
• Navigate to the Import, Settings page
• Follow the instructions and import your posts

It does not usually happen instantly so be patient once you have completed the import process.

Pixelfed's Import expects all your images to have related captions for the images. If not, the captionless images will not import. There is a great article on how to fix this here: https://anders.thoresson.se/post/2025/01/preparing-your-instagram-export-for-pixelfed-import/