Purge all files using API Tokens


I create new API Token with following permissions:

All zones - Zone Settings:Edit, Zone:Edit, Cache Purge:Edit

Then I am trying to purge all files sending following request:

POST /client/v4/zones/zone_id/purge_cache HTTP/1.1
Host: api.cloudflare.com
Connection: close
Authorization: Bearer my_token
Content-Type: application/json
Content-Length: 25


In response I got error 500 - Internal Server Error and no more additional informations.
Is it bug or maybe I am doing something wrong?