Give the Binance key its permissions

Still on Binance: restrict to A9's IP, then tick trading — never withdrawals.

The steps, in words

1. Open Edit on the new key
   A key is created with reading only. Tap Edit on the key you just made to turn trading on.
2. Tick the trading permissions
   Tick Enable Spot, Margin & Stock Trading, and Enable Futures if you will run shorting strategies. Leave Enable Withdrawals off: no platform should be able to move your funds, and A9 rejects a key that can.
3. Restrict to A9's IP, then save
   Under IP access restrictions choose Restrict access to trusted IPs only, paste A9's IPv4 shown here, tap Confirm, then Save. Binance asks for the security codes once more.