Creating full stack iOS notes app: findOneAndUpdate

Hi team: I’ve been googling this all day but can’t figure out my error, I’ve reached the end of Ali’s Mongodb and node.js tutorial but keep getting a null error with my code:
I can create, fetchAll and delete notes but can’t update. I think this must mean that the id search query is finding nothing but can’t see the typo/error! Any advise would be great!!

app.post("/update", (req, res) => {
    Data.findOneAndUpdate(
        {
        _id: req.get ("id") }, 
        
        {title: req.get ("title"),
        date: req.get ("date"),
        note: req.get("note")
     },
        
    (err) => {
        console.log ("Failed to update ", + err)
    })
    res.send ("Updated")
})