For Desktops
- Open your LinkedIn account.
 - Open your Profile Page and copy the link from the URL.
 - Paste the link in the LinkedIn URL Box and you are done.
 
For Mobiles:
- Open the LinkedIn app.

 - Go to your Profile

 - Scroll to the bottom of your Profile Page
 - In the contact section, you will find your LinkedIn profile link

 - Press and hold to copy the link
 - Paste it in the form box and you are done