Bigcommerce License Activation
To assign a license to the BigCommerce store, go to Partner Portal > Licenses and click the Add License button. Here is a direct link to add a new license
Add the store Domain and select the platform as BigCommerce and Click the Add License button to submit the form.
You will be redirected to the BigCommerce App store to log in and select the domain of available BigCommerce domains on your account. There, you will be able to install the app. Then, you would need to confirm the activation of the Salestio license.
After the license is activated, you will see the active status in the Licenses list.