I know some will put comment like this post is duplicate of so many questions, but I\'ve tried many ways to achieve Access Token in linkedin Oauth. Explaining what i tried.<
Finally I am happy to post my answer after so much search. Every step I did is correct only, but one thing I was missing here like, Linkedin API doesn't supports CORS.
I tried implementing Javascript SDK, that works like charm. But API wasn't. Then I found very helpful Link which says I need to implement Rest API from backend by allowing CORS, not from front end.
Make sure to follow all the points which I mentioned above in my post. And for Allow CORS follow this link. You will get data but only basic profile of user according to LinkedIn Terms data can be accessible
Hope this post may help someones time to search more