Depending on your account size, you might need to upgrade to add more locations into Local Viking for management. The steps to follow vary if you signed up with PayPal or with Credit Card.
PayPal: Message support and request to upgrade.
Stripe (CC): If you're the owner of the account, you can access upgrade/downgrade/updating your CC inside your billing tab in your Local Viking account.
Click on the Billing button
and choose the plan that you like
Here is more information on the plans https://localviking.com/pricing
If you have any questions please contact customer support