Follow the below instructions for create your Criteo Client Id and Secret
Sign in to Criteo at using your Criteo login credentials.
Expand the menu and click on Team under Settings
Click on Create New User button under API Users - REST API list
Enter an mail address (one who integrates Criteo on Daton) and select role as View Only. Client Id and Secret will be generated when you hit the Add User button. Copy the Client Id and Secret and save it someplace safe as secret will not be displayed again. You are required to provide these details while integrating Criteo on Daton.
Please note that Daton would require only read access to extract the data from Criteo.