To find your Zasilkovna API credentials click on this link or go to your Packeta client and click on the name of your account in the top right corner of the navigation bar.
Zasilkovna API key
The API key is used mainly in the Zasilkovna widget (map with pick up-points) to load your settings into it. If the API key is not correct it won't show the specific country and partner settings.
Zasilkovna API password
API password is used for sending and receiving information from Zasilkovna. We require it for our Advanced plan, so we can send orders to Zasilkovna directly from Shopify and save the tracking code and status of the order to Shopify in return.
And lastly, Sender Indication can be found at this address. Copy out the Sender Indication and paste it to the Shopify app. This is only mandatory if you have more than one sender in Zasilkovna admin.