ETS - Can't translate using API Key - Not Authorized response


I am trying to use SDL ETS API to post translation, but getting Not Authorized response. What is wrong ? Do you have API documentation online ?

I am using following curl:

curl -X POST -H "Content-type: application/json" -H "Authorization: LC apiKey=ag_vgxK6w24o5eL" -d '{"text":"سلام دنیا", "from":"fa", "to":"eng"}' http://10.X.X.X:8001/api/v1 Get exception: Not Authorized
Root Cause:
incorrectly used API call.
SDL ETS REST API is a version specific and it is not available online, but it is only included in each build.

 you'll find REST API documentation under SDL_ETS_7_x_x_win64_installer\docs\api\rest\

Once SDL ETS is installed you can find REST API under :
c:\Program Files\SDL\SDL ETS\docs\

correct REST API call  :

curl -X POST -u ag_vgxK6w24o5eL: -d mode="text" -d sourceLanguageId="per" -d targetLanguageId="fra" -d text="2LPZhNin2YUg2K/ZhtuM2Kc=" 10.X.X.X:8001/.../quick"

-the source text has to be Base64 encoded.