You can connect LinkedIn from Settings->Connect, click on the Connect LinkedIn button:

If you are not already logged in to LinkedIn on your browser, you will be taken to the LinkedIn login screen.

Login to linkedIn using the credentials that has access to the LinkedIn profile and company pages you want to connect.

You will be asked to grant permission to The Real Estate Voice:

Click Allow.

You should now be redirected back to the TREV dashbaord and you will see which profiles and pages are available.