To enable locations in Local Brand Manager, navigate to the 'Locations' tab at the top of your screen.

From there, you'll see gray entries. That means those locations are disabled in the account for management.

Example:

You have a few options to enable the location:

One way is to look at the 3 horizontal dots on the far right.

Click on those and, you'll see the "Enable location" slider:

Another way to enable is to click on the location. From there, you'll see this option:

The third way to enable a location is to click on your email in the top right corner and select the "Google Accounts" tab.

From there, select the Google Account associated with that location by clicking the email. Once you've navigated into that page, you'll see slider buttons next to all the locations:

The last method is meant for bulk enabling/disabling, but you can use it for a single location as well. Just check the desired listings on the 'Locations' tab and a menu will appear on the top of the list: