The provided key element does not match the schema - Javascript - node.js

Question

I'm generating some data and trying to insert it in the database.
const AWSXRay = require('aws-xray-sdk');
const AWS = AWSXRay.captureAWS(require('aws-sdk'));
const documentClient = new AWS.DynamoDB.DocumentClient();
module.exports = {
batchWriteItems: async function (tableName, headers, data) {
// AWS only allows batches of max 25 items
while (data.length) {
const batch = data.splice(0, 25);
const putRequests = batch.map((elem) => {
// Overide field type (default is String)
let items = {};
for (let key in elem) {
const header = headers.find((hdr) => hdr.name === key);
items[key] = {
[header.type]: elem[key],
}
}
return {
PutRequest: {
Item: items,
},
};
});
const params = {
RequestItems: {
[tableName]: putRequests,
},
};
console.log(JSON.stringify(params));
await documentClient.batchWrite(params).promise();
}
},
};
The table is correct, Partition key is countryCode (S) and there is no sort key.
If I copy the items individually and create an item manually in DynamoDB, it works!
I don't see any issues here but I'm still getting this error:
The provided key element does not match the schema
console.log(JSON.stringify(params));
{
"RequestItems":{
"test-table":[
{
"PutRequest":{
"Item":{
"countryCode":{
"S":"LX"
},
"value":{
"N":"0.67"
}
}
}
},
{
"PutRequest":{
"Item":{
"countryCode":{
"S":"AF"
},
"value":{
"N":"0.68"
}
}
}
}
]
}
}
Do you see any issue here? I'm kinda stuck