Login to your Bitfinex account and click on profile icon on top right
Then click on API from drop down list
Click on Create new API Key
Now, label your API key with any label you'd like to (we recommend to use a separate API key for each service you use and label them accordingly), make sure to give permission to "Wallets" and click on "Generate API key"
You need to check your email and go through the link
After clicking on the link sent via email, you will see a screen with QR code, your API Key and API Secret. Like below
Now go to Coin Stats app Altfolio tab, scroll far to the right and click Add new portfolio by Selecting Exchange (API KEYS).
Click QR and scan the QR code presented by Bitfinex or copy/past your KEY and Secret Manually.
After clicking Add you will see your Bitfinex portfolio synced with the Coin Stats app.