Page Admin level access to the Company's page is required to pull LinkedIn Social data. Once connected, you will need to select the Company ID for us to pull data from the API.
Note: LinkedIn's API requires users to reconnect EVERY 60 DAYS for security reasons. This means that you'll just need to go into the LinkedIn credential within Channelmix Control Center, click the edit button next to the credential, and then select "Reconnect". This process will need to be done at least once every 60 days. So long as the user is logged into an account that has proper access to the LinkedIn account, there is no harm caused by excessive reconnecting. It is also recommended that you setup up some type of alert system to reconnect your connections, so that access isn't lost and follower data isn't missed.
For more details around reconnecting data sources within ChannelMix Control Center, please read this article.