"Network error" while calling a REST api from Outlook app, but 200 Ok from outllook web (Outlook.com) - outlook-web-addins

Question

I was building an outlook add-in for which i need to call a rest api. While sideloading the add-in in the outlook application in my Mac it is throwing the error below. But, in the outlook.com it is working perfectly fine (200 Ok response). I might be missing something, don't know what. I couldn't fix it. Please help me fixing this problem.
Thanks!!
{
"message": "Network Error",
"name": "Error",
"stack": "createError#https://localhost:3000/vendor.js:613:24\nhandleError#https://localhost:3000/vendor.js:104:25\nwrapFn#https://localhost:3000/polyfills.js:1231:48\nonInvokeTask#https://localhost:3000/vendor.js:34970:43\nrunTask#https://localhost:3000/polyfills.js:180:61\ninvokeTask#https://localhost:3000/polyfills.js:493:45\ninvokeTask#https://localhost:3000/polyfills.js:1634:24\nglobalZoneAwareCallback#https://localhost:3000/polyfills.js:1660:31",
"config": {
"url": "http://localhost:8102/api/get-token",
"method": "post",
"headers": {
"Accept": "application/json, text/plain, */*"
},
"transformRequest": [
null
],
"transformResponse": [
null
],
"timeout": 0,
"xsrfCookieName": "XSRF-TOKEN",
"xsrfHeaderName": "X-XSRF-TOKEN",
"maxContentLength": -1
}
}