paypal integration with firebase functions has errors in logs - firebase

Question

I am trying for 3 days to solve this problem but I couldn't.
what I am doing is integrating paypal payment with my android application using firebase cloud functions.
I integrated paypal successfully on my android app. but when i shifted to the second step which is making http triggered function to complete integration I used this code on index.js on cloud functions.
const functions = require('firebase-functions');
const paypal=require('paypal-rest-sdk');
const admin=require('firebase-admin');
admin.initializeApp(functions.config().firebase);
paypal.configure({
mode:"sandbox",
client_id:functions.config().paypal.client_id,
client_secret:functions.config().paypal.client_secret
});
//Create and Deploy Your First Cloud Functions
// // https://firebase.google.com/docs/functions/write-firebase-functions
//
exports.payout = functions.https.onRequest((request, response) => {
const sender_batch_id = Math.random().toString(36).substring(9);
const sync_mode ='true';
const payReq = JSON.stringify({
sender_batch_header: {
sender_batch_id: sender_batch_id,
email_subject: "You have a payment"
},
items: [
{
recipient_type: "EMAIL",
amount: {
value: 0.1,
currency: "USD"
},
receiver: "ammah6600#crowns.com",
note: "Thank you.",
sender_item_id: "item_3"
}
]
});
paypal.payout.create(payReq,sync_mode,(error,payout) =>{
if(error){
console.warn(error.response);
response.status('500').end();
throw error;
}else{
console.info("payout created");
console.info(payout);
response.status('200').end();
}
});
});
****but**
I found these problems in Logs of firebase functions**
1-
`
{ name: 'SYNC_MODE_NOT_APPLICABLE',
message: 'Synchronous mode will soon be deprecated and is no longer available for new integrations. You can use the asynchronous mode by specifying sync_mode= false in the request.',
debug_id: '393880ab5b7a9',
information_link: 'https://developer.paypal.com/docs/api/payments.payouts-batch/#errors',
httpStatusCode: 403 }`
2
-Error: Response Status : 403
at IncomingMessage.<anonymous> (/user_code/node_modules/paypal-rest-sdk/lib/client.js:130:23)
at emitNone (events.js:91:20)
at IncomingMessage.emit (events.js:185:7)
at endReadableNT (_stream_readable.js:974:12)
at _combinedTickCallback (internal/process/next_tick.js:80:11)
at process._tickDomainCallback (internal/process/next_tick.js:128:9)
Then I changed sunc_mode to false but i found these problems appeared to me:
1-
{ name: 'INSUFFICIENT_FUNDS',
debug_id: 'b2a6e96353ee7',
message: 'Sender does not have sufficient funds. Please add funds and retry.',
information_link: 'https://developer.paypal.com/docs/api/payments.payouts-batch/#errors',
httpStatusCode: 422 }
2-
Error: Response Status : 422
at IncomingMessage.<anonymous> (/user_code/node_modules/paypal-rest-sdk/lib/client.js:130:23)
at emitNone (events.js:91:20)
at IncomingMessage.emit (events.js:185:7)
at endReadableNT (_stream_readable.js:974:12)
at _combinedTickCallback (internal/process/next_tick.js:80:11)
at process._tickDomainCallback (internal/process/next_tick.js:128:9)
Please help me in reviewing my codes or credentials
regarding that my country is egypt
my merchant account is us also receiver account