Export text file of burned items

Install wkof: Installing Wanikani Open Framework
Open the JavaScript console with either F12, Ctrl+Shift+I or Ctrl+Shift+J

And then run the script here by pasting it in:

wkof.ready("ItemData").then(() => {
    wkof.ItemData.get_items({wk_items: {filters: {item_type: "voc", srs: "burn"}}}).then((kanji) =>
        console.log(kanji.map((k) => k.data.slug).join(",")))

I have no clue how migaku expects the output format to be, but this should in theory result in a comma separated list of all vocabularies, that should be easy to modify into a json format