Create entire new document or update existing in mongodb using mongoose (nodejs)

Question

Hi all I am trying to create a new document or update it if it exists

here is the code

 if (!isMemberr) {
        const newSubscription = new membership({
            user_id: req.body.user_id,
            plan_id: req.body.plan_id,
            transaction_id: req.body.transaction_id
        });
        newSubscription.update({ upsert: true, setDefaultsOnInsert: true }).then(() => {
            res.status(201).json({
                Status: 201,
                Message: "Subscription Created",
                Data: newSubscription
            })
        })

        const filter = { _id: req.body.user_id };
        const update = { member: true };
        let updatedStatus = await User.findOneAndUpdate(filter, update);
        updatedStatus.member;
        plan()

the issue is if a particular document already exists then it is updating it but when I delete the document and call the API it is not giving any error or does not create a new document.