Go to Binance
Log in or create a new account on https://www.binance.com/.
You should open futures account first
You can't create API for futures before you have an active futures account.
Switch to futures on Binance.
Open the futures account.
Create a new API key
Continue with steps below once you have a created API, don't add it to 3Commas yet.
Edit the key
Just after you've created the key, click "Edit restrictions."
Check "Enable Future"
Connect Binance Futures to 3Commas
Don't modify other settings.