In order to generate an API key and client ID, you will need to login into your
1cart administration panel (usually through https://<your_domain>.1cart.eu/admin.
From there you will need to open the API tab of the configuration section. It will
list all currently created client IDs, but not the key attached to them. These are
available only during creation, so make sure to save them somewhere safe
for latel retrieval!
You probably will not have any keys generated at this point, so go ahead and click
the new API key button. It will immediately create a new pair of API key (apiKey)
and client id (clientId). Again, save these somewhere safe, because there will
not be an option to retrieve the key later on!