Getting LinkedIn access token through http request on node.js server - node.js

Question

I am following the Authorization Code Flow (3-legged OAuth) documentation and I am now at step 3 where I need to use the authorization code in order to recieve an access token from LinkedIn. In the project I am using node.js, typescript and the node-fetch library. The following function creates a body with content type x-www--form-urlencoded since this is content type which LinkedIn require.
async function GetAccessToken(data: any) {
let body: string | Array<string> = new Array<string>();
for (let property in data) {
let encodedKey = encodeURIComponent(property);
let encodedValue = encodeURIComponent(data[property]);
body.push(encodedKey + "=" + encodedValue);
}
body = body.join("&");
const response = await fetch("https://www.linkedin.com/oauth/v2/accessToken", {
method: 'POST',
headers: {'Content-Type': 'application/x-www-form-urlencoded; charset=UTF-8'},
body: body
}).then((res: any) => {
console.log("Result", res);
});
return response;
}
I do not recieve any errors and the response status is 200 but the response values I recieve are:
size: 0,
timeout: 0,
and what LinkedIn promise is:
access_token
expires_in
When I post the url with my parameters using postman the request goes through and I recieve the correct data which indicates the problem lies within my request function and not my values.
Any help is appreciated!

Answer 1

You need add all headers from postman
const urlencoded = new URLSearchParams();
urlencoded.append("client_id", env.LINKEDIN_CLIENT_ID);
urlencoded.append("client_secret",env.LINKEDIN_CLIENT_SECRET);
urlencoded.append("grant_type", "authorization_code");
urlencoded.append("code", code);
urlencoded.append(
"redirect_uri",
"http://localhost:3000/api/auth/linkedin-custom"
);
const accessTokenPromise = await fetch(
"https://www.linkedin.com/oauth/v2/accessToken",
{
method: "POST",
headers: {
"Content-Type": "application/x-www-form-urlencoded",
},
body: urlencoded,
}
);