Paypal api – Express Get route return error 500:"Cast to ObjectId failed for value"

i need some help please, i try to seed some data to mongoDB Atlas, so i code (thanks Basir^^) a api for this :

productRouter.get('/seed', expressAsyncHandler(async (req, res) => {
console.log('foo');
/*     await Product.remove({})*/
const seller = await User.findOne({
    isSeller: true
})

if (seller) {
    const products = data.products.map((product) => ({
        ...product,
        seller: seller._id,
    }));
    const createdProducts = await Product.insertMany(data.products);
    res.send({
        createdProducts
    });
} else {
    res.status(500).send({
        message: 'No seller found. first run /api/users/seed'
    });
}}));

the problem, when i enter my api route in the browser he return this :

"Cast to ObjectId failed for value "seed" at path 
"_id" for model "Product""

The other routes works perfectly, i’m really confused…

This is the productSchema:

import mongoose from 'mongoose'
import {
    reviewSchema
} from './reviewSchema.js'

const productSchema = new mongoose.Schema({
    name: {
        type: String,
        required: true,
        unique: true
    },
    seller: {
        type: mongoose.Schema.Types.ObjectId,
        ref: 'User',
    },
    image: {
        type: String,
        required: true,
    },
    brand: {
        type: String,
        required: true,
    },
    category: {
        type: String,
        required: true,
    },
    description: {
        type: String,
        required: true,

    },
    price: {
        type: Number,
        required: true,

    },
    countInStock: {
        type: Number,
        required: true,
    },
    rating: {
        type: Number,
        required: true,
    },
    numReviews: {
        type: Number,
        required: true,
    },
    reviews: [reviewSchema]
}, {
    timestamps: true
})

export const Product = mongoose.model("Product", 
productSchema)

this my server.js :

import {config} from 'dotenv'
import express from 'express'
import mongoose from 'mongoose'
import path from 'path'
import{productRouter}
from'./routers/productRouter.js';
import {userRouter} from './routers/userRouter.js'
import {orderRouter} from './routers/orderRouter.js'
import {uploadRouter} from 
'./routers/uploadRouter.js';

const dotenv = config();

const app = express();
app.use(express.json());
app.use(express.urlencoded({
extended: true
}));

mongoose.connect(process.env.MONGODB_URL || 
'mongodb://localhost/ecommercelab', {
useNewUrlParser: true,
useUnifiedTopology: true,
useCreateIndex: true
});

app.use('/api/uploads', uploadRouter);

app.use('/api/users', userRouter);

app.use('/api/products', productRouter);

app.use('/api/orders', orderRouter);

app.get('/api/config/paypal', (req, res) => {
res.send(process.env.PAYPAL_CLIENT_ID || '');
});

app.get('/api/config/google', (req, res) => {
res.send(process.env.GOOGLE_API_KEY || '');
});

const __dirname = path.resolve()
app.use('/uploads', 
express.static(path.join(__dirname, 'uploads')));

app.use(express.static(path.join(__dirname, 
  '/frontend/build')));

app.get('*', (req, res) => {
  res.sendFile(path.join(__dirname, 
'/frontend/build/index.html'));
});

app.use((err, req, res, next) => {
res.status(500).send({
    message: err.message
 });
});

const port = process.env.PORT || 5000;
app.listen(port, () => {
  console.log(`Serve at http://localhost:${port}`);
});

Its for a Ecommerce app.

Thanks for your attention, i continue to test on my side 😉