The response lists the languages you can declare in an application context.

Unauthorized.

Forbidden. You don't have the access this operation needs, or your account isn't entitled to a feature the request uses, such as a rule, the MODIFY action, or languages. The detail says which access or entitlement to ask for.

Internal server error. Something failed on Akamai's side. Try again later. If it keeps happening, contact Akamai support with the instance value.