Sorry, the configuration panel leads to a misunderstanding. You can ignore it for IPU-Chart Basic, downloaded here from the WordPress directory.
The functionality described in the description section of the plugin works without any license key. If it doesn’t work there is an other issue – certainly not a missing license key.
A license key is only needed if you’ve installed one of the extensions IPU-Chart Multi-Series or IPU-Chart Editor (which are described on our website).
We will change the configuration panel in our next update. So the plugin will ask for a key only if you’ve actually installed one of the extensions.