Linkedin API Setup
Go to https://yourdomain.com/admin/developer-settings/platform-settings
Or click to Developer Settings > Platform Settings > linkedin
Then
Go to https://developer.linkedin.com/ (opens in a new tab)
Or click to My Apps

- Click My APPS
- Click Create App
- Fill Up all informations and create app
- Enable and apply request Share on LinkedIn and Sign In with LinkedIn using OpenID Connect
- copy LINKEDIN REDIRECT URI and add this to Authorized redirect URLs
- Copy the credentials
and paste the credentials here
And click Save Changes button.