Substack to OPML (run in JS console from reads page)

index.js

(async () => {
    const handle = await window.showSaveFilePicker({
        suggestedName: 'substack.opml',
        types: [{ description: 'OPML File', accept: { 'text/x-opml': ['.opml'] } }],
    });
    const writable = await handle.createWritable();
    let opml = await (await import("https://esm.sh/opml-generator")).default
    let q = Array.from(document.querySelector("#entry > div.reader-nav-root.reader2-font-base > div.reader-nav-page > div > div > div > div:nth-child(3) > div.pencraft.pc-display-flex.pc-flexDirection-column.pc-paddingBottom-20.pc-reset.flex-fill-uYLRqz > div").children)
    
    await writable.write(opml({ title: "Substack" },
        q.map((el) =>  
            new Object({ xmlUrl: el.href + "/feed", title: el.innerText.split("\n")[0]}) 
        )
    ))
    await writable.close();
})()