passkit-generator: pass generate api stream is undefined

Hi, I am getting undefined stream on using the following code. I dont see any error in my catch either. Please help as I am relatively new to this. The stream is undefined.

app.get('/downloadpass', async (req, res, next) => {
 let examplePass = new Pass({
     model: "./passModels/Coupon",
     certificates: {
         wwdr: "./certs/wwdr.pem",
         signerCert: "./certs/signerCert.pem",
         signerKey: {
             keyFile: "./certs/passkey.pem",
             passphrase: "12345"
         }
     },
     overrides: {
         // keys to be added or overridden
         serialNumber: "AAGH44625236dddaffbda"
     },
     // if true, existing keys added through methods get overwritten
     // pushed in queue otherwise.
     shouldOverwrite: true
 });
  
 // Adding some settings to be written inside pass.json
 examplePass.barcode("36478105430"); // Random value
  
 // Generate the stream, which gets returned through a Promise
 try {
  let stream = await examplePass.generate();
  stream.pipe(res)
  
} catch (e) {
  //this will eventually be handled by your error handling middleware
  console.log(e) 
}
})