invalid redirect_uri. This value must match a URL registered

I think you need to have correct value in Authorized Redirect URLs values. Follow below link:

 

https://naveengopisetty.wordpress.com/2014/09/15/linkedin-oauth-2-0-issue-invalid-redirect_uri-this-value-must-match-a-url-registered-with-the-api-key/ 

 

https://developer.linkedin.com/docs/oauth2

 

https://stackoverflow.com/questions/26570194/linkedin-invalid-redirect-uri-this-value-must-match-a-url-registered-with-the