How to resolve Cloud Function Error:401 Unauthorized - authentication

Question

I have coded an Apps Script that creates an event in the Calendar.
Apps Script is stand alone, and event in also created in my personal Gmail account.
This Script is linked to GCP project linked to same account as Script.
Oauth consent screen is created in the GCP account and also credentials for Oauth2.0 client ID.
Now I created a cloud function to call this appsScript but it is giving an Error:401
following is code for the cloud function
let message = req.query.message || req.body.message || 'Hello World!';
const axios = require('axios');
const {google} = require('googleapis');
//Authorization
const { GoogleAuth } = require('google-auth-library');
const auth1 = new GoogleAuth({
keyFile: 'credentials.json',
scopes: ['https://www.googleapis.com/auth/drive','https://www.googleapis.com/auth/drive.metadata'
, 'https://www.googleapis.com/auth/calendar','https://www.googleapis.com/auth/calendar.events' ],
});
const drive = google.drive({version: 'v3', auth: auth1 });
const calendar = google.calendar({version : "v3"});
//calling formSchedule function with all the variables
async function formSchedule(eventDate,claimId, garageId, claimDet,startTime,cEmailG){
//Schedule Meeting Json Data
var evDurtion=30;
var startDateTime = startTime;
var endDateTime=new Date(startDateTime.getTime()+(evDurtion*60000));
// console.log(endDateTime)
var subject="Claim ID : "+claimId+' - Call';
var attendees=[{
"email": garageId,
},
];
var eventData={
"summary":subject,
'start': {
'dateTime': startDateTime,
'timeZone': 'Asia/Kolkata'
},
'end': {
'dateTime': endDateTime,
'timeZone': 'Asia/Kolkata'
},
"attendees":attendees,
"conferenceData": {
"createRequest": {
"conferenceSolutionKey": {
"type": "hangoutsMeet"
},
"status": {
"statusCode": "success"
},
"requestId": "test1235"
}
},
"description":claimDet,
"defaultReminders": [
{
"method": "popup",
"minutes": "5"
}
]
}
console.log("after all variables initialization")
// Schedule Meeting
axios({
method: "post",
url : //API Executable deployed Apps Script link,
data: {
'eventdata' : eventData,
'serviceId' : cEmailG
},
headers: {
'Content-Type': 'text/plain;charset=utf-8',
},
}).then(function (response) {
try{
console.log('Event Added Successfully.')
}
catch (error){
console.log('------error-----',error)
}
})
}
res.status(200).send(message);
};```