Login to your BitMex account and click API.
In API Keys section click API Key Management.
Enter Name (ex. CoinStats BitMex) and leave other fields unedited for read-only access. Click Create API Key.
Then you will see a screen like below with your ID and Secret keys.
Please make sure to copy/paste your Secret Key to a safe place, as it will only be displayed at the time it is created. If you lose this key, you will need to delete your API and set up a new one.
Now go to CoinStats app Portfolio tab, swipe far to the right and click Connect Exchange.
Select BitMex from the list and paste your ID and API Secret.
After clicking Submit you will see your BitMex portfolio synced with the CoinStats app.
Refer to support in case of further questions. Hope you'll enjoy!