Azure Function get MS Graph access token

getmsgraphaccesstoken.js

async function getMSGraphAccessToken() {

    var body = {
        grant_type: 'client_credentials',
        client_id: process.env.AZURE_APP_ID,
        client_secret: process.env.AZURE_APP_SECRET,
        resource: 'https://graph.microsoft.com'
    };

    var responseText = await request('https://login.windows.net/' + process.env.AZURE_TENANT_ID + '/oauth2/token', { method: 'POST', body, format: 'urlencoded' });
    var access_token = JSON.parse(responseText).access_token;
    return access_token;
}