title: (node:17891) UnhandledPromiseRejectionWarning: TypeError: newPay.save is not a function
body: <p>the console is logging the user but whenever i add the save method i get the error above, any help will be nice<code>enter code here</code>
  this is my controller;</p>
  <pre><code> paymentPost: async(req, res, err)=&gt;{
     let {plan, amount, payID} = req.body
     let userID = req.body
     userID = payID
     if(!payID || !plan || !amount){
      res.json({
        message: &quot;all field required&quot;
      })
     } else{
    await User.findOne({userID}).then(async(userId)=&gt;{
       if(!userId || userID.length&lt;9){
         res.status(400).json({
          message: &quot;No user with this ID&quot;,
         })
       }else 
        await Payment.findOne({},async (err, payer)=&gt;{
          if(!payer){
              let newPay = []
              newPay.push(new Payment({
              payID,
              amount,
              plan,
              status:true
        }))
        console.log(newPay)
        return newPay.save()
        .then(res.status(200).json({
          message: &quot;Payment successfull&quot;,
          newPay
        }))
         }
       
     })
    }
   },
  </code></pre>
  <p>i just need the user to save to database</p>