Why do I keep getting this error? Iam using nodejs, and am not that familiar with backend programming, so I cant really know whats going on, If anyone is fimiliar with this error or knows what causing, PLEASE HELP ME🙏🙏😌

Here is my code??

    async function verify() {
        const ticket = await client.verifyIdToken({
            idToken: token,
            audience: CLIENT_ID,  // Specify the CLIENT_ID of the app that accesses the backend
        });
        const payload = ticket.getPayload();
        const userid = payload['sub'];
      }
      verify()
      .then(()=>{
          res.cookie('session-token', token);
          res.send('success')
      })
      .catch(console.error);

})

const stripe = require('stripe')(process.env.STRIPE_PRIVATE_KEY)


app.post("/create-checkout-session", async (req,res)=>{
    try{
const session = await stripe.checkout.sessions.create({
payment_method_types:['card'],
mode:'payment',
line_items: req.body.items.map(item=>{
    
    return{
        price_data:{
            currency:item.currency,
            product_data:{
                name:item.name
            },
            unit_amount: item.priceInCents,
        },
        quantity:item.quantity
    }
}),
success_url:`${process.env.SERVER_URL}/success.html`,
cancel_url:`${process.env.SERVER_URL}/cancel.html`
})
res.json({url:session.url})
    }catch(e){
res.status(500).json({error:e.message})
    }
    
    res.json({url:'Hi'})
})````