rest - Instagram Private API: method "upload/photo" return 502 err code -

send request:

post https://i.instagram.com/api/v1/upload/photo/
http/1.1 host: i.instagram.com
accept: /
x-ig-capabilities: 3q4=
user-agent: instagram 10.26.0 android (18/4.3; 320dpi; 720x1280; xiaomi; hm 1sw; armani; qcom; en_us)
content-type: multipart/form-data, boundary=08115eb7e9ab4b2d91cbd909da597f68
accept-encoding: gzip, deflate, sdch
accept-language: en-us
x-ig-connection-type: wifi
cookie: sessionid=igsce75d8682d023c3fb49d8f36d6b3baaa1d65fb1de6ec3a2e60093609dc641736b%3azysykn402331ai9xkwqurrcsdvv4sw5g%3a%7b%22_auth_user_id%22%3a5967392865%2c%22[...]
connection: close
cookie2: $version=1
content-length: 76564

--08115eb7e9ab4b2d91cbd909da597f68
content-disposition: form-data; name="upload_id"

1505336507000
--08115eb7e9ab4b2d91cbd909da597f68
content-disposition: form-data; name="_uuid"

08115eb7e9ab4b2d91cbd909da597f68
--08115eb7e9ab4b2d91cbd909da597f68
content-disposition: form-data; name="_csrftoken"

uhaoop90msx2wm5ezh697ijftjfazurr
--08115eb7e9ab4b2d91cbd909da597f68
content-disposition: form-data; name="image_compression"

{"lib_name":"jt","lib_version":"1.3.0","quality":"87"}
--08115eb7e9ab4b2d91cbd909da597f68
content-disposition: form-data; name="photo"; filename="pending_media_1505336507000.jpg"
content-type: image/jpeg content-transfer-encoding : binary

ffd8ffe000104a46494600010101006000600000ffe100e645786966000049492a00080000000[...]

--08115eb7e9ab4b2d91cbd909da597f68--

in response receiving "http/1.1 502 bad gateway". in may problem?

ps sorry 4 english