Normally a private key is created on the Intra2net system and there is no means to export it. Only certificates and public keys issued for the key can be imported using System > Keys > Own Keys : CA menu.
However, if you have a ready pair of private and public keys and want to import them, you can import them using with thebutton under System > Keys > Own keys.
The pair of keys can be imported either by cut&paste in PEM format but the private key cannot be password protected. Alternatively, the pair of keys can be imported as a PKCS#12 file. You must enter the correct password protecting the file.
Before importing a pair of keys, make sure that you know exactly where it was created and whether this source and the route are fully trustworthy. Anyone who knows the private key can make the data transferred with this key legible. Never let an external Certificate Authority generate a pair of keys, generate the keys locally and send only the certificate request to the external Certificate Authority. Do not allow key pairs to be generated in a web browser, as this will create additional means of attack.