Step 1: First, you need to Go to the LinkedIn Developers website
Step 2: Here, Click on Create Application button.
Step 3: Fill in the form that appears next to register the new application. PS: Website URL must be your Store URL like http://www.yourstore.com.
Step 4: After filling the form click Submit to submit the form and keep your API Key and Secret Key safe.
For LinkedIn, redirect URL is optional, if you want set redirect URL, then set as: https://your-domain.com/auth/linkedin/callback
Step 5: Now you can use these API details in your LinkedIn social login module to let your customers log in to your website using their LinkedIn account.