Behance uses OAuth2 for its auth mechanism.
Register a new application at Behance App Registration, set your application name, website and redirect URI.
Fill Client Id and Client Secret values in the settings:
SOCIAL_AUTH_BEHANCE_KEY = ''
SOCIAL_AUTH_BEHANCE_SECRET = ''
Also it’s possible to define extra permissions with:
SOCIAL_AUTH_BEHANCE_SCOPE = [...]
Check available permissions at Possible Scopes. Also check the rest of their doc at Behance Developer Documentation.