LinkedIn has a very restrictive API, so only company pages can be added at this time (not personal or school pages). In addition, you must connect a personal LinkedIn account on your Connected Social Accounts page that is an administrator for the company page, in order to display the company posts. So, you must "own" the LinkedIn company page you want to display.
Please note the following other restrictions of the LinkedIn API:
- Feeds cannot display video posts from LinkedIn.
- Feeds cannot link to individual posts within LinkedIn. Clicking a post will take you to the front of the LinkedIn company page.
- Feeds can only obtain approximately 10 historical posts for a LinkedIn company page. We can then obtain new posts going forward.