API Error: User not found!

[sexavet94]

Medium API doesn't work.
I have created an APP and authorized my user. Fetched the access_token successfully.
But when I try to fetch an authorized user's info, I have gotten the below error message:
{"errors":[{"message":"User not found","code":6004}]}

These are the logs:
http://prntscr.com/qarjrp
http://prntscr.com/qark4h

I have tried to create a new "Integration tokens" from my User settings and tried to use it instead of the access token. But the same result. I can not get authorized user's information.
What is wrong? Could you help me, please?
I have contacted the Medium support team several times. But their support is very bad. They reply very late and every time writes unrelated messages.

Thanks in advance.