If you want to use Sellvia in two or more WordPress stores with one subscription, you will need to have separate API keys for each site.
However, please note that you will not be able to have two free turnkey stores under one subscription - these stores are limited to one per a subscription. But if you have a Shopify store or a Wordpress store with Woocommerce or Alidropship installed on them, you can install and activate Sellvia app/plugin in them without subscribing again.
Open Sellvia.com → Account page and use access details in the email to log into your Sellvia account.
Now click the 'Stores' tab and then click the green plus button in the top right corner of the page to have a set of Sellvia API keys ready for your site. The keys will be marked with the yellow Not Active status
Click on the arrow to see the keys and copy the public and secret keys that you created in your Sellvia account and paste them to the corresponding fields in your WordPress site → Sellvia → API keys and click 'Activate'.
You can have up to 10 active keys, meaning you can run Sellvia on ten WordPress stores with just one Sellvia account.
But if you have a Shopify store, one Sellvia subscription can be used on one site only.