Under the head tag
<script type="text/javascript" src="//platform.linkedin.com/in.js">
api_key: xxxxxxxxx
authorize: true
// onLoad: onLinkedInLoad
//scope: r_basicprofile r_emailaddress
</script>
<a href="javascript:void(0)" class="btn btn-default btn-linkedin" onclick='call_linkedin()'>
<i class="fa fa-linkedin-square" aria-hidden="true"></i> <span>Sign In With LinkedIn</span> </a>
<script type="text/javascript">
function call_linkedin() {
if(IN.User.authorize()){
getProfileData();
}else{ IN.Event.on(IN, "auth", function() {getProfileData();});}
}
// Use the API call wrapper to request the member's profile data
function getProfileData() {
IN.API.Profile( "me" ).fields( "id", "first-name", "last-name", "headline", "location", "picture-url", "public-profile-url", "email-address" ).result( displayProfileData ).error( onError );
}
// Handle the successful return from the API call
function displayProfileData( data ) {
console.log(data)
}
</script>
Please try this and let me know