curl -s https://api.kite.trade/session/refresh_token \It says "Token is invalid or has expired", but the token is still valid and I can very well send quote requests with it.
-H "X-Kite-Version: 3" \
-d "api_key=" \
-d "refresh_token=" \
-d "checksum=sha256( api_key + access token + api secret )"
You can take a look at this thread.