To create API keys on Bittrex exchange please go to Bittrex website: https://bittrex.com
Log in into your account. If you do not have an account yet, create it by clicking on "Sign Up" tab.
Go to Settings on the upper right hand corner.
On the settings page, select "API Keys" and click "Add new key ...".
Enable the following options for the API key: READ INFO, TRADE LIMIT и TRADE MARKET. Click on "Safe".
Enter the "Key" and "Secret" to activate exchange connection function on Investy platform.