Your screenshot shows you in the correct Cisco licensing portal.
When you click "Next" you should be issued an activation key that you then use to add the no-cost 3DES-AES license to the ASA. (assuming you aren't in an export-restricted area and have accepted the terms and conditions)
The process for adding it is either via the ASDM GUI (Configuration > Device Management > Licensing > Activation Key) or command line interface ("activation-key <key id>").
