I don’t own it but I found this one

• Go to (malscraper.azurewebsites) and export the lists (anime/manga) you want by entering the source platform and your username on that platform, and download the file.

• Go to this Anilist import settings page (anilist.co/settings/import) to import the lists (you must be logged in with the account) and upload to the correct section the correct list you downloaded earlier

Or if you follow strict FOSS principles and rather use open-source alternatives, there’s this project on GitHub github.com/metacritical/anhilist---