Polar allows you to export all your flashcards and import them to Anki
You can download all flashcards in the annotation viewer at the top right. This feature is available to all Plus/Pro users
The export supports both front/back and cloze deletions flashcards, and conserves text formatting (bold, italics,...)
By default, all flashcards are downloaded into one deck (titled something like polar-anki-deck)
If you want to download only flashcards in a specific folder or with specific tags, you can first select that folder or tag in the annotation viewer and then download them. You can export the flashcards into separate decks by tagging the relevant flashcards with deck:chem101.