Alpaca has no futures
Not “not yet” — they do not offer them. A strategy that trades MNQ, ES or NQ cannot be pointed at an Alpaca account, and Tradeus refuses the subscription when you set it up rather than failing at the first live alert.
Alpaca issues you a key pair from your own dashboard. Paper and live are separate accounts with separate keys on separate addresses — a paper key is simply refused by the live one. A paper account is free, needs no verification, and is the sensible place to start.
What the two halves can do
Shares
Bought and sold as usual. Alpaca can hold a stop and a target on the order itself, though Tradeus does not use that yet — see below.
Crypto
Market and limit orders only. Alpaca accepts no attached stop or target on crypto at all, and crypto cannot be sold short.
Stops
Because one account covers both halves, Tradeus holds your stop itself rather than leaving it with the broker. The trade log says so on every order.
Shorts
No sell opens a short on Alpaca. A sell reduces or closes what you hold and stops there.
Crypto is spelled with a slash at Alpaca — BTC/USD where your chart says BTCUSD. Tradeus translates both ways, so your alerts keep the name you already use.